EXCHANGE 


University  of  Texas  Bulletin 

No.  2230:     August  8,  1922 


Notes  on  the  Oil  and  Gas  Fields  of 
Webb  and  Zapata  Counties 

The  Underground  Position  of  the  Austin 

Formation  in  the  San  Antonio 

Oil  Fields 


BY 
E.  H.  SELLARDS 


Bureau  of  Economic  Geology  and  Technology 

Division  of  Economic  Geology 
J.  A.  Udden,  Director  of  the  Bureau  and  Heatf  of  the  Division 


PUBLISHED  BY 
THE  UNIVERSITY  OF  TEXAS 

AUSTIN 


Publications  of  the  University  of  Texas 

Publications  Committee : 

FREDERIC  DUNCALF      J.  L.  HENDERSON 
G.  C.  BUTTE  E.  J.  MATHEWS 

KILLIS  CAMPBELL        H.  J.  MULDER 
F.  W.  GRAFF  A.  E.  TROMBLY 

HAL  C.  WEAVER 

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E44-8C2-2m 


University  of  Texas  Bulletin 


Xo.  22,'JO:      Ai.feiisfc  8,  11 


Notes  on  the  Oil  and  Gas  Fields  of 
Webb  and  Zapata  Counties 

The  Underground  Position  of  the  Austin 

Formation  in  the  San  Antonio 

Oil  Fields 


BY 
E.  H.  SELLARDS 


Bureau  of  Economic  Geology  and  Technology 

Division  of  Economic  Geology 
J.  A.  Udden,  Director  of  the  Bureau,  and  Head1  of  the  Division 


PLRL1SHED    BY     THE    UNIVERSITY    FOUR    TIMES     A     MONTH,     AND     ENTERED     AS. 

SECOND-CLASS    MATTER    AT    THE    POSTOFFICE    AT    AUSTIN, 

TEXAS,   UNDER  THE  ACT  OF  AUGUST   24,   1912 


:  .j  ••**  ,•."••  ?    .  ,•,  •*; 
.''??•:  i.'-: :..:;".../ 


The  benefits  of  education  and  of 
useful  knowledge,  generally  diffused 
through  a  community,  are  essential 
to  the  preservation  of  a  free  govern- 
ment. 

Sam  Houston. 


Cultivated  mind  is  the  guardian 
genius  of  democracy.  .  .  It  is  the 
only  dictator  that  freemen  acknowl- 
edge and  the  only  security  that 
freemen  desire. 

Mirabeau  B.  Lamar. 


EXCHANGE 


CONTENTS 

Notes  on  the  Oil  and  Gas  Fields  of  Webb  and 
Z  a  pat  a  Counties 

PAGE 

SUratigraphic  Geology 5 

Regional  Dip 6 

Topographic  Features 6 

Location  of  the  Oil  and  Gas  Fields  with  Respect  to  Topo- 
graphic Features..  . 8 

Charco-Redoiido  Wells 8 

Jennings  Gas  Field 0 

The  Mirando  Pool. 9 

The  Riser  Gas  Field 10 

The  Schott  Pool 10 

The  Carolina-Texas  Oil  Company  Gas  Wells. 11 

Well  Records 12 

Well  Logs  in  Webb  County 13 

Well  Logs  in  Zapata  County 24 

The  Underground  Position  of  the  Austin  Formation 
in  the  San  Antonio  Oil  Fields 

PAGE 

Introduction 30 

General  Structural  Conditions  in  the  San  Antonio  District.  .  32 

Contour  Map  on  the  Austin  Formation 33 

Structural  Conditions  as  Indicated  by  Contouring    on    the 

Austin  Formation 34 

Relation  of  Producing  Wells  to  Structure 37 

Producing  Formations    38 

Well  Records 38 

LIST  OF  ILLUSTRATIONS 

PAGE 

Map  of  Webb  and  Zapata  County  Oil  Fields 7 

Map  Showing  Underground  Position  of  Austin  Formation .  .  35 


977634 


NOTES  ON  THE  OIL  AND  GAS  FIELDS  OF  WEBB  AND 
ZAPATA  COUNTIES: 


BY  E.  H.  SELLARDS 


At  the  present  time  oil  or  gas  is  being  obtained  from  several 
localities  in  Webb  and  Zapata  counties.  The  localities  include 
the  Charco  Redondo  oil  wells,  Jennings  gas  pool,  and  Mirando 
oil  pool  in  Zapata  County,  and  the  Reiser  gas  wells  and  Schott 
oil  pool  and  the  gas  wells  of  the  Carolina-Texas  Oil  Com-, 
pany  in  Webb  County.  Of  these  several  localities,  the  Reiser 
field  is  the  oldest  as  a  commercial  field,  having  been  discovered 
in  1909,  although  previous  to  that  time  oil  had  been  noted  in 
shallow  wells  drilled  for  water  at  the  Charco  Redondo.  Ranch. 
The  following  notes  011  the  producing  fields  of  these  two  counties 
are  based-  on  a  reconnaisance  of  about  ten  days  made  in  April 
and  May,  1922. 

Stratigraphic  Geology 

At  the  March  meeting  of  the  American  Association  of  Petro- 
leum Geologists,  Dr.  A.  C.  Trowbridge  read  a  paper  on  the 
Coastal  Plains  formations  in  Texas,  adjacent  to  the  Rio  Grande, 
which  it  is  understood,  will  be  published.  Not  wishing  to  antici- 
pate in  any  way  the  results  given  in  this  paper  by  Trow- 
bridge, the  geology  and  stratigraphy  of  this  area  will  be  referred 
to  at  this  time  only  in  a  very  general  way. 

Immediately  at  Laredo  and  for  a  few  miles  to  the  east,  the 
rocks  exposed  in  the  stream  beds  and  rock  cuts  are  chiefly  sand- 
stones, often  glauconitic,  probably  representing  the  Cook  Moun- 
tain formation.  Next  to  the  east  and  extending  almost,  if  not 
quite,  to  Reiser,  is  a  broad  belt  in  which  clays  predominate, 
although  some  oyster  shell  beds  are  included.  These  clays  rep- 
resent the  Yegua  formaton.  About  twenty-two  miles  east  of 
Laredo  (three  miles  west  of  Reiser)  is  found  a  belt  of  very 
sandy  land  which  may  possibly  represent  a  remnant  of  the 

Manuscript  submitted  for  publication  August,  1922.  Issued  Sep- 
tember, 1922. 


6  I'nh'ersity  of  Texas  Bulletin 

Fayette,  or  a  sandy  horizon  in  the  Yegua.  At  Reiser  and  in 
a  clay  pit  nearby,  are  seen  clays  and  oyster  shall  beds  not 
unlike  those  of  the  Yegua. 

Next  east  of  Reiser,  near  Aguilares,  and  extending  thence 
north  and  south  is  a  belt  of  country  in  which  the  land  is  in 
places  sandy  and  in  which  there  ar$  occasional  outcrops  of  a 
light-colored  rock  with  a  limited  amount  of  sand.  This  rock, 
which  in  places  is  chietiy  volcanic  ash  containing  plant  impres- 
sions,- probably  represents  the  Fayette  formation.  Next  to  the 
east  is  found  a  belt  of  clay  land  which  widens  in  the  northern 
part  of  Webb  County  and  possibly  represents  the  Frio  formation. 

About  thirty-five  miles  east  of  Laredo  is  a  prominent  escarp- 
ment beyond  which  the  land  is  level  and  slopes  gradually  to 
the  east.  The  formation  capping  this  escarpment  is  the 
Reynosa,.  which  consists  of  caliche  filled  gravel  and  in  places  of 
caliche  rock.  The  age  of  this  formation  is  either  Pleistocene  or 
Pliocene.  In  the  face  of  the  escarpment,  underneath  the 
Reynosa  capping,  there  is  found  in  places  a  coarse  sandstone 
which  may  be  of  Miocene  age. 

It  is  thus  seen  that  the  formations  found  at  the  surface  are 
chiefly  those  of  the  Eocene  series,  together  with  possibly  limited 
Miocene  exposures,  and  in  the  eastern  part  of  these  two  counties, 
the  Reynosa  limestone  and  gravels.  Adjacent  to  the  stream  beds, 
of  course,  are  Pleistocene  and  recent  terrace  deposits, 

Regional  Dip 

The  regional  dip  in  this  area  is  to  the  east.  To  the  north  and 
northeast  of  this  area,  the  strike  of  both  Eocene  and  Cretaceous 
formations  is  northeast-southwest,  the  dip  being  southeast.  In 
the  central  and  southern  parts  of  Webb  and  in  Zapata  counties, 
the  strike  of  the  Eocene  formations  is  approximately  north- 
south,  the  dip  being,  as  stated,  to  the  east.  The  average  rate 
of  dip  has  not  been  determined. 

Topographic  Features 

In  traveling  east  from  Laredo,  it  is  to  be  noted  that  for  several 
miles,  after  crossing  Chacon  Creek,  the  country  is  characterized 


Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    1 


TORCCILLAS  ! 

----.  cole  Petroleum  **1 

^ 


MAP  OF 

WEBB  AND  ZAPATA  COUNTY 
OIL  FIELDS- 
SCALE 


•  ••        /     5TARR  CO. 


8  University  of  Texas  Bulletin 

by  successive  minor  ridges  which  trend,  in  general,  north-south. 
These  ridges  have  a  rather  abrupt  west  face  and  represent  west 
facing  escarpments,  marking  the  outcropping  edges  of  east 
dipping  strata.  In  some  instances  the  escarpments  are  held  up 
by  a  hard  stratum  consisting  chiefly  of  oyster  shell  rock.  About 
eleven  miles  east  of  Laredo  the  land  becomes  more  nearly  level. 
Just  east  of  Mirando  City  is  the  pronounced  Keynosa  escarp- 
ment to  which  reference  has  already  been  made. 

Location  of  the  Oil  md  Gas  Fields  with  Respect  to  the 
Topographic  Features 

The  Charco-Redondo  and  Jennings  fields  are  located  in  or 
near  the  belt  of  country  referred  to  above  as  probably  repre- 
senting the  Fayette  formation.  Each  of  these  localities  is 
some  distance  from  the  Reynosa  escarpment,  the  Charco-Redondo 
locality  being  possibly  seven  miles,  and-  the  Jennings  field  prob- 
ably not  quite  so  far.  The  Reiser  gas  field  is  likewise  seven 
or  eight  miles  west  of  the  Reynosa  escarpment.  On  the  other 
hand,  the  Mirando  and  Schott  pools  and  the  gas  wells  of  the 
Carolina-Texas  Company  are  located  immediately  at  the  foot 
of  this  escarpment.1 

Charco-Redondo  Wells 

The  Charco-Redondo  oil  wells  are  located  in  the  southeastern 
part  of  Zapata  County.  The  wells,  now  producing,  are  shal- 
low, varying  from  135  to  160  feet  in  depth.  The  oil  is  from 
sands  and  sandy  shales,  slightly  greenish  in  color,  found  asso- 
ciated with,  and  usually  underlying  an  oyster  shell  stratum, 
which  serves  as  cap-rock.  About  twenty-one  wells  have  been 
drilled,  of  which  sixteen  are  now  being  pumped,  the  produc- 
tion being  from  one  to  three  barrels  per  day  per  well. 

The  oil  sand  at  this  locality  dips  to  the  east.  Thus  the  west- 
ernmost of  the  wells  obtain  production  at  a  depth  of  from  135 
to  140  feet,  while  wells  farther  to  the  east  on  land  of  equal 
or  lower  elevation  find  the  oil  sand  at  from  150  to  160  feet. 
About  one  mile  west  of  the  oil  wells  there  is  a  west  facing 


gas  wells  more  recently  obtained  by  the  Carolina-Texas 
Company  one  is  reported  to  be  located  on  the  escarpment. 


Notes  on  Oil  and  Gets  Fields  of  Webb  and  Zapata  Counties     9 

scarp  held  up  by  an  oyster  shell  stratum.  This  oyster  shell 
bed  is  probably  the  same  as  that  associated  with  the  oil  sand, 
indicating  the  eastward  dip  in  the  formations. 

The  producing  sands  at  this  locality  are  probably  in  the  Fay- 
ette formation.  The  oil  has  a  gravity  of  about  18.5  B,  and  is 
said  to  yield  a  good  quality  of  lubricating  oil. 

The  Jennings  Gas  Field 

The  Jennings  Gas  Field  is  located  in  the  northeastern  part  of 
Zapata  County,  about  seven  miles  from  the  east  and  nine  miles 
from  the  north  county  line.  This  field  was  discovered  in  1914 
when  a  test  well  for  water  obtained  gas.  Ten  or  more  wells 
have  been  drilled.  Two  of  these,  failing  to  obtain  gas,  were 
drilled  to  a  greater  depth  and  obtained  fresh  water  at  about 
1900  feet.  The  yield  in  the  gas  wells  is  said  to  be,  for  each 
successful  well,  between  ten  and  twelve  million  cubic  feet  initial. 

Surface  exposures  of  the  light  colored  slightly  sandy  rock  with 
strata  of  volcanic  ash  provisionally  referred  to  the  Fayette 
formation  were  observed  four  or  five  miles  northwest  of  the 
Jennings  Field.  No  exposures  were  seen  immediately  within 
the  gas  fields,  but  it  is  probable  that  the  surface  formation  at 
this  locality  is  Fayette.  The  gas  horizon  at  this  locality  lies 
between  1200  and  1300  feet  below  the  surface.  It  seems  prob- 
able that  the  gas  horizon  is  within  the  Yegua  formation,  although 
formation  thicknesses  at  this  locality  are  not  fully  determined. 

The  Mirando  Pool 

The  Mirando  Pool  is  located  in  the  northeastern  part  of  Zapata 
County,  about  two  miles  from  the  east  and  three  from  the 
north  county  line.  The  discovery  well  in  this  field  was  com- 
pleted' in  the  spring  of  1921.  Since  that  time  drilling  has 
been  actively  continued  in  this  field.  These  wells  are  located 
at  the  foot  of  the  Reynosa  escarpment,  and  at  a  place  where, 
as  indicated  on  the  sketch  map,  the  escarpment  bends  abruptly 
to  the  east. 

The  producing  sands  in  this  field  lie  at  a  depth  approximating 
1450  feet  from  the  surface.  The  wells  are  about  seven  miles 


10  University  of  Texas  Bulletin 

north  and  five  miles  east  of  the  Jennings  gas  pool.  Since  the 
regional  dip  is  to  the  east,  if  the  gas  at  Jennings  is  from  the 
Yegua,  it  seems  probable  that  the  oil  at  Mirando  Pool  is  like- 
wise from  this  formation.  On  this  point,  however,  the  evidence 
is  at  present  inconclusive.  The  logs  of  the  deep  wells  in  and 
near  this  pool  indicate  that  sandstones  are  entered  at  about 
1700  feet. 

The  wells  at  the  west  edge  of  the  Mirando  Pool  produce  gas, 
while  in  the  central  part  of  the  pool  the  wells  yield  oil  with 
but  little  gas.  The  oil  is  from  21.5  B  gravity,  and  is  said  to 
contain  very  little  gasoline. 

The  Reiser  Gas  Field 

The  Reiser  Gas  Field,  in  Webb  County,  is  located  on  and 
near  the  Texas-Mexican  Railway,  twenty-five  miles  east  of 
Laredo.  About  twelve  gas  wells  have  been  obtained  at  this; 
locality,  the  best  of  which  are  reported  to  have  made  twenty  or 
twenty-five  million  cubic  feet  of  gas  per  day.  Formerly  the 
gas  from  this  field  supplied  Laredo,  but  is  used  at  the  present 
time  only  for  local  purposes. 

The  chief  gas  horizon  at  Reister  is  found  at  a  depth  of  from 
650  to  800  feet.  Probably  the  gas  in  this  field  is  obtained  from 
the  Yegua  formation,  although,  as  in  the  case  of  the  other  fields 
in  this  area,  the  age  of  the  producing  horizon  cannot  be  regarded 
as  definitely  determined. 

The  Schott  Pool 

The  Schott  Pool  is  located  about  thirty-five  miles  east  of 
Laredo,  and  one  and  one-half  miles  south  of  Mirando  City. 
The  discovery  well  in  this  field  was  completed  December,  1921. 
This  pool  is  located  near  the  foot  of  the  Reynosa  escarpment. 
The  country  is  somewhat  rolling,  and  there  are  occasional  hills 
remaining  as  outliers  or  remnants  of  the  Reynosa  formation. 

The  producing  horizon  of  the  Schott  Pool  is  found  at  a  depth 
of  from  1525  to  1550  feet.  About  three  miles  southwest  of 
this  pool  are  exposures  which  appear  to  represent  the  Fayette 
formation  from  which  it  seems  probable  that  the  wells  of  the- 


Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    11 

Schott  Pool,  like  those  of  the  Mirando  Pool,  start  near  the  top 
of  the  Eocene.  Production  in  the  Schott  Pool  is  being  obtained 
from  seventy-five  to  one  hundred  feet  deeper  than  in  the 
Mirando  Pool,  the  surface  elevation  being  essentially  the  same. 
Whether  or  not  production  in  the  Schott  Pool  is  from  the 
same  horizon  as  in  the  Mirando  Pool  is  undetermined  at  this 
time.  At  Mirando  City,  some  oil  has  been  obtained  at  a  depth 
of  about  1630  feet. 

A  well  located  about  three-fourths  of  a  mile  northwest  of  the 
Schott  Pool  apparently  passed-  the  oil  producing  horizon  at 
about  1635  feet.  This  well  continuing  to  a  greater  depth  en- 
countered a  thick  body  of  slightly  sandy,  blue  and  pink  some- 
what calcareous  shale  which  was  penetrated  to  a  depth  of  2500 
feet,  where  sandstones  were  encountered. 

In  the  Schott  Pool  as  in  the  Mirando  Pool,  gas  is  found  in 
wells  west  of  those  producing  oil,  apparently  marking  the  west 
margin  of  the  pool.  The  producing  sands  as  indicated  by  the 
wells  dips  to  the  east  with  possibly  a  structural  nose.  The  oil 
of  the  Schott  Pool  appears  to  be  very  similar  in  character  to 
that  of  the  Mirando  Pool.  The  well  of  the  Kanoka  Oil  Com- 
pany in  the  Schott  Pool,  after  being  cleaned,  produced  not 
less  than  800  barrels  per  day. 

The  Carolina-Texas  Oil  Company  Gas  Wells 

The  Carolina-Texas  Oil  Company  has  a  well  from  which  gas 
has  been  obtained,  located  about  seven  miles  east  of  north  of 
Torrecillas.  This  well  is  at  the  foot  of  the  Reynosa  escarpment, 
and  at  a  place  where  a  small  stream  enters  from  the  highland, 
forming  a  reentrant  in  the  margin  of  the  scarp. 

Some  gas  was  obtained  in  this  well  at  1295  feet,  but  the  prin- 
cipal gas  horizon  is  reported  at  a  depth  of  2015  feet,  The  for- 
mation from  which  the  gas  is  obtained  is  undetermined.  This 
well  is  about  ten  miles  north  and  four  miles  east  of  the  Schott 
Pool.  A  second  well  drilled  at  this  locality  obtained  some  gas 
at  1296  feet.1 


3Two  additional  wells  drilled  since  this  manuscript  was  submitted 
and  located  east  of  the  first  two  wells  are  reported  to  have  obtained 
gas. 


12 


University  of  Texas  Bulletin 
Well  Records 


A  summary  of  representative  wells  in  these  two  counties  is 
given  in  the  table  which  follows.  In  addition  a  number  of  logs 
are  included  indicating  the  drilling  conditions  in  the  several 
fields. 

Summary  of  Representative  Wells  in  "Webb  and  Zapata  Counties 


Name  of  Well. 

Location.                Depth. 

Remarks  . 

Oarolina-Texas  Oil  Co._ 

Surv.     268,     7    miles    N. 
N.  E.  of  Torrecillas  

2015 

Gas  show  at  1270-1279.     Gas 
at  2015. 

Zapata  Oil  and  Gas  Oo. 

Charco  Redondo 

1735 

Oil    sand    at    163-168.      Gas 
show  in  sand  at  932-965. 

Texas  Company. 
Jennings  No    4 

Jennings  Gas  Field. 

1%  mi.  N.  W.  of  Ranch 
House 

3015 
1367? 

1234? 

Fresh  water  at  196tf. 

12  M  gas  at  1265-1357.     Rock 
pressure  455  Ibs. 

9  M  gas  at  1229-1234.     Rock 
pressure  4<?0  ibs. 

Jennings  No    3 

2V3  mi.   N.   E.   of  Ranch 
House    - 

Cuellor  No.  1  .      —    —  - 

U£    mi.     E.     N.     E.     of 
Ranch  House  

Tveeton  Synd.  No.  2  

Mirando  Oil  Co.  No.  2_ 
Mirando  Oil  Co.  No.  3. 
.Mirando  Oil  Co.  No.  4a 
Mirando  Oil  Co.  No.  7- 

Witherspoon     Oil      Co. 
No     4              

Mirando  Pool. 

N.  W.  pt.  of  pool.    Blk. 
23 

1467 
1502 
1426 
1453 

1490 

2000 
1460 

1476 
1730 

Gas  at  1445-1467. 
Show  of  oil  at  1447-1452. 
Producer.    Discovery  Well. 
Oil  sand  at  1433-1442. 

Oil  sand  1470-1476.    100  bbls. 
Sandrock  1735-2000. 
Reported  producing.   80  bbls. 

Gas  well,  sand  1443-145-".. 
Reported  dry. 

S.  pt.  of  pool.    Blk.  5__ 
S.  pt.  of  pool.    Blk.  5__ 
S.  pt.  of  pool.     Blk.  5- 
Central  pt.  of  pool.    Blk. 
17 

N.  pt.  of  pool.    Blk.  18. 
Central  part  of  pool  

Witherspoon     Oil     Oo. 
No     1 

Tenn-Zapata      Oil      Co. 
No     1 

S.  W.  pt.  of  pool.     Blk. 
16 

Zapata    Red.     &     Ref. 
Oo                    

Surv.  113.     S.  of  pool  

Producers  Oil  Com- 
pany. 
B.    &   M.   No.    5  (Com- 
pleted    by     Brethwith 
&   Allison) 

Reiser  Gas  Field. 
Near  Reiser 

2598 

j     2240 
€85 

Water  at  about  1800  ft. 
Sands  200  ft.   from  surf. 
Gas  reported  at  2500  ft. 
Mineral  water  at  1500±. 
Gas  in  use  for  local  supply. 

Reiser  No.  1  ._  

1  mi     E.   of  Reiser 

RiCiser  No    4 

Af     P/iiocir 

Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    13 

Summary  of  Representative  Wells  in  Webb  and  Zapata  Counties — Continued 


Name  of  Well. 

Location. 

Depth. 

Remarks. 

Kanoka  Oil  Co.  No.  1. 

Schott  Pool. 

N.    Central  pt.    of  pool. 
Blk.    6—         

1559 

Oil    sand    at    1545-1559.      Re- 

Laurel  Oil  Oo.  No.  1—  _ 
Leaseholders      Oil     Co. 
No     1 

W.  pt.  of  pool.    Blk.  9. 
W.  pt.  of  pool.    Blk.  10 

1539 
1599 

portted    making1   800   bbls. 
per  day. 
Gas  well. 

Gas  well. 

Schott  Oil  Co.   No.  2.. 

Central  pt.  of  pool.    Blk. 

11  

1532 

Gas  and  oil  at  1530-1532 

Sehott   Oil  Co.    No.   3— 
Schott   Oil  Co.   No.   1— 

South  Plains  Oil  &  Gas 
Co. 

E.  part  of  pool.     Blk.  12 
West  of  pool.    Sur.  462_- 

N.  W.  of  pool.     Sur.  460 

1588 
1750 

2500 

Oil  at  1571-1588. 
Ends  in  red  and  blue  shale 
and  gumbo. 

Below    1600    chiefly    red    and 

Laredo  Oil  Co.  No.  2— 

In  Mirando  City      -    — 

1635 

blue  shales. 
Oil  at  about  1635. 

Well  Logs  in  Webb  County 

The  following  logs  of  wells  in  Webb  County  are  arranged 
alphabetically  according  to  owners  of  the  land  on  which  the 
wells  are  located,  and  the  company  owning  the  well. 

tog-  of  Albercas   No.   1,  Albercas   Oil  Co.,  Survey  836,  About   Three   Miles 
North   Slig-htly  West   of  the   Mirando   Pool 


Depth  in  Feet. 


From. 

To. 

ness. 

Red  sandy  clay                                          _ 

0 

42 

42 

Blue  clay  and  boulders    

42 

79 

37 

Shale 

79 

132 

53 

Gumbo   -                  -  —          -    

132 

142 

10 

Shale  and  boulders  _  _.       

142 

163 

21 

Green  ''hale  and  boulders 

163 

246 

83 

Lime  rock 

246 

250 

4 

Hard  sandy  shale 

250 

281 

31 

Blue  and  green  gumbo   and  shale 

281 

410 

129 

Hard  gummy  shale                             -                     -  

410 

506 

93 

Shale  and  boulders                                             - 

506 

613 

107 

Water  sand 

613 

671 

58 

Gumbo 

671 

710 

3f) 

Gummy  shale  and  boulders          _            

710 

778 

68 

Shale  and  sand,  oil  showing. 

778 

789 

11 

Hard  shale          ..                                              -—  - 

789 

S40 

51 

Packed   sand                                    

840 

871 

31 

871 

961 

90 

961 

092 

31 

992 

1,055 

63: 

1,055 

1,142 

87 

1,142 

1,172 

30 

Shale  and!  boulders                    -       «  

1,172 

1,280 

108 

Hard  sandy  shale... 

1,280 

1,309 

23 

University  of  Texas  Bulletin 


Log-  of  Albercas  No.  i,  Albercas   Oil  Co.,   Survey  836,  About  Three   Miles 
North   Slig-htly   West   of  the    Mirando   Pool— ^Continued 


Depth  in  Feet. 

Thick- 
ness. 

j 
From.  1    To. 

Gumbo    

1,309 
1,318 
1,445 
1,480 
1,491 
1,505 
1,507 
1,548 
1,550 
1,559 
1,585 
1,€61 
1,684 
1,709 
1,720 

1,727 
1,734 
1,739 

1,318 
1,445 
1,489 
1,491 
1,505 
1,507 
1,548 
1,550 
1,559 
1,535 
1,601 
1,684 
1,709 
1,720 
1,727 

1,734 
1,739 
1,797 

9 
127 
44 
2 
14 

9 

4i 

9 
26 
76 
23 
25 
11 
7 

7 
5 
58 

Hard  and  soft  shale,  blue  and  brown  _ 

Shale  and  boulders 

^Packed   sand 

Hard  shale 

Lime  rock 

Hard  shale,  pyrites  and  boulders  __ 

Ifime  rock    _. 

'Gumbo           -    _ 

Xhale  and  boulders  --    

Hard  gumbo        -    --  

Hard  shale                                    

Hard  shale  and  boulders                                              -  

Hard  sand  rock,  showing  gas. 

Soft    "ind                                                                               -  

Hard  shale    total  depth                                          

Began  December  7,  1921;  completed  February  11,  1922;  set  8",  casing  at  743';  set  6*  cas- 
ing at  1735';  1  ft.  in  reck.  8"  casing  leftt  in  hole  and  derrick  left  standing  with  inten- 
tion of  drilling  deeper. 

Log-  of  Barusly  No.   1.     Carolina  Texas  Oil  Co.     Survey   268,  About   Pour 
Miles  Northeast  of  Mirando  City 


Depthi 

n  Feet. 

Thick- 

From. 

To. 

ness. 

Clay 

a 

22 

Rock                                                               -                            

22 

48 

26 

Sand                                                                       

56 

8 

Rock                                                                        

56 

59 

3 

Shale                                                             —  —    

59 

72 

13 

Sand                                                          

72 

77 

5 

77 

103 

26 

Rock 

103 

108 

5 

108 

141 

'        1 

Rock                                                                                 --    

141 

142 

1 

Sand                                                                   _      

142 

160 

18 

Rock                                                                                  

160 

162 

») 

162 

195 

33 

Rock                                                                                 

195 

197 

2 

197 

217 

20 

217 

220 

3 

Sand                                                                        

228 

8 

Rock 

228 

229 

1 

Sandy  shale                                                                                _____ 

229 

254 

25 

254 

260 

6 

Sand                                                                               _      

260 

270 

10 

Sand  and  boulders                                               -                 

270 

310 

40 

Rock                                                                                   -  

310 

312 

2 

Sand  boulders                                        

312 

375 

63 

Rock                                                             

375 

380 

5 

380 

402 

22 

Gumbo                                           -  

402 

407 

5 

407 

428 

21 

Pay                   .  

428 

435 

435 

440 

5 

Snnrl    and   boulders  

440 

460 

20 

Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties   15 

Log-  of  Barusly  No.  1.     Carolina  Texas  Oil  Co.     ssurvey  268,  About  FOur 
Miles  Northeast  of  Mirando  City — Continued 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Bock                 _      —         _.      

460 

464 
610 
616 
630 
760 
764 
780 
796 
827 
835 
910 
916 
930 
970 
1,000 
1,002 
1,060 
1,065 
1,070 
1,085 
1,088 
1,130 
1,135 
1,137 
1,155 
1,168 
1,195 
1,222 
1,226 
1,270 
1,295 

1,401 
1,466 
1,535 
1,550 
1,568 
1,573 
1,600 
1,608 
1,654 
1,685 
1,700 
1,725 
1,732 
1,800 
1,815 
1,827 

464 
610 
616 
630 
760 
764 
780 
796 
827 
835 
910 
916 
930 
970 
1,000 
1,002 
1,060 
1,065 
1,070 
1,085 
1,088 
1,130 
1,135 
1,137 
1,155 
1,168 
1,195 
1,222 
1,226 
1,270 
1,295 
1,322 

1,466 
1,535 
1,550 
1,568 
1,573 
1,600 
1,608 
1,654 
1,685 
1,700 
1,725 
1,732 
1,800 
1,815 
1,827 
1,995 

4 
146 
6 
14 
130 
4 
16 
16 
31 
8 
75 
6 
14 
40 
30 
2 
58 
5 
5 
15 
3 
42 
5 
2 
18 
13 
27 
27 
4 
44 
25 
27 

65 
69 
15 
18 
5 
27 
8 
46 
31 
15 
25 
7 
68 
15 
12 
168 

Sandv  shale  and  boulders 

Gumbo                                —  

Water   sand                                  _    _    

Pink   gumbo                                                           -         

Sand  and  boulders                      _>             -                          -  —    - 

Gas   sand                                                                             --    > 

Sand  and  boulders                                                               -      

Pay    sand                                                            -    -      --      -  —  —  - 

Sand  and  boulders                                    -    -               -     —  

Bock                                                       _          

Sand                                                              _     

Rock                                               -         

Gumbo                                               -  

Pfl  V 

Clay   (?)                                           -    -    

No  log  1,322  to  1,401.     This  well  deepened  by  Trussle,  Brown 
&  Hodges. 
Sandy  shale                                     -  

Shale  and  boulders                            -       --              -    —  

Sand                                                                                                 

Shale  and  boulders                                                                      -  -- 

Shale                                                                        

Hard  shale                                             --       -~  -  -  

Shale                        -       

Shale                                          

Total  depth,  2,015.     Shale  grades  into  sandy  shale  and  apparently  into  a  coarse 
grained  sandstone,  which  is  producing  aboutl  8  M  cu.  ft.  gas. 


16 


University  of  Texas  Bulletin 


Log-  of  Breckenridse  No.  1,  South  Plains  Oil  &  Gas  Co.,  Survey  No.  460, 

Southeast   Corner  of  Block   15,  About  One   Mile 

Southwest  of  Mirando  City 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Surface  clay 

0 
20 
72 
120 
122 
240 
261 
272 
349 
400 
422 
428 
451 
471 
474 
487 
620 
628 
670 
680 

% 

772 
815 
830 
882 
892 
905 
940 
951 
958 
998 
997 
1,040 
1,060 
1,135 
1,155 
1,160 
1,212 
1,219 
1,282 
1,286 
1,327 
1,331 
1,348 
1,393 
1,426 
1,441 
1,444 
1,460 
1,470 
1,488 
1,498 
1,502 
1,506 
1,509 
1,547 
1,556 
1,579 
1,595 
1,603 
1,604 

20 
72 
120 
122 
240 
261 
272 
349 
400 
422 
428 
451 
471 
474 
487 
620 
623 
670 
680 
710 
771 
772 
815 
830 
882 
892 
905 
940 
951 
958 
993 
997 
1,040 
1,060 
1,135 
1,155 
1,160 
1,212 
1,219 
1,282 
1,286 
1,327 
1,331 
1,348 
1,393 
1,426 
1,441 
1,444 
1,460 
1,470 
1,488 
1,498 
1,502 
1,506 
1,509 
1,547 
1,556 
1,579 
1,595 
1,603 
1,604 
1,685 

20 
52 
48 
2 
118 
21 
11 
77 
51 
22 
6 
23 
20 
3 
1? 
133 
3 
47 
10 
30 
61 
1 
43 
15 
52 
10 
13 
35 
11 
7 
35 
4 
43 
20 
75 
20 
5 
52 
T 
63 
4 
41 
4 
17 
45 
33 
15 
3 
16 
10 
18 
10 
4 
4 
3 
38 
9 
23 
16 
8 
1 
31 

Yellow  clay  and  boulders-- 

Bed  clay  and  shale 

Lime   rock 

Hard  shale  and  boulders.. 

Gumbo     -  

Lime  rock  

Hard  green  shale  and  bou 
Shale    —  

Iders 

Chalk  rock  .. 

Gumbo    

Shale 

Packed    sand 

Hardi  lime  rock    _. 

Gumbo 

Soft  gummy  shale 

Soap  stone 

Soft   shale  

Gumbo     -      

Hard  shale    _.    

Lime  rock- 

Shale  and  boulders 

Gumbo 

Hard  shale 

Sand   rock 

Soft  lime  rock 

Shale  and  boulders 

Hard  ilme  rock 

Gumbo 

Soft  shale       

Sand  rock 

Hard  sandy  shale  

Water    sand  -    -            — 

Hard  shale 

Sandy  shale 

Gumbo 

Soft   shale 

Gumbo 

Hard  sandy  shale  and  bou 
Lime   rock  

Iders 

Hard  shale  and  streaks-  of 
Sand  rock 

gumbo    

Sandy  shale 

Gumbo 

Hard  shale  and  boulders  - 

Sandy   shale 

Soft  shale 

Hard   gummy  shale  
Shale  and  boulders 

Hard  sandy  shale 

Soft  sandy  shale;   set  8"  p 
Shell    rock  _.  

ipe                    

Sand    _ 

Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    17 


log-  of  Breckenridg-e  No.  1,  South  Plains  Oil  &  Gas   Co.,  Survey  NO.  46O, 

Southeast  Corner  of  Block  15,  About  One  Mile 

Southwest  of  Mirando  City — Continued 


Depth  in  Feet. 

mK}«-i, 

From. 

ness. 
To. 

Sandy  shale;  set  liner  and  bs 
Shale 

iled 

1,635 
1,641 
1,660 
1,665 
1,725 
1,731 
1,741 
1,747 
1,751 
1,784 
1,785 
1,831 
1,860 
1,866 
1,947 
1,957 
1,872 
1,998 
2,004 
2,015 
2,021 
2,036 

1,641               6 
1,660             19 
1,665               5 
1,725             60 
1,731              6 
1,741            10 
1,747              6 
1,751              4 
1,784             33 
1,785              1 
1,831             46 
1,860             29 
1,866              6 
1,947             81 
1,957             10 
1,972             15 
1,998             26 
2,004               6 
2,015             11 
2,021               6 
2,036;            15 
2,055;            19 
2,060!              5 
2,061               1 
2,067,              6 
2,100             33 
2,106!              6 
2,128             22 
2,176             43 
2,180               4 
2,186              6 
2,195               9 
2,202:              7 
2,240!            38 
2,300             60 
2,360|            63 
2,405             45 
2,475!            70 
2,476               1 
2,480               4 
2,500             20 
2,527:            27 
2,540             13 
2,542[             2 
2,550,              8 
2,562             12 
2,578!           16 
2,588             10 
2,591               3 
2,603             12 
2,623             20 
2,630               7 
2,665             35 
2,689|            24 
2,6X>!              1 
2,709             19 
2,726             17 
2,746             20 
2,775            29 
2,8021            27 
2,807;              5 
1  fflfi                Q 

Gumbo    - 

Green  shale    

Gumbo 

Packed    sand 

Shale 

Gumbo 

Hard  blue  shale          

Pink  shale 

Green  shale,  soft   and  hard  j 
Pink  shale  and  lime  streaks 

streaks 

Blue   gumbo 

Pink  shale  with  streaks  of  gi 
Gyp     gumbo 

imbo 

Hard  pink  shale 

Blue  shale.         

Gumbo       _    . 

Pink   shale  __. 

Gumbo              -      

Hard  blue  shale  

Blue   gumbo    -  

2,055 
2,060 
2,061 
2,067 
2,100 
2,106 
2,128 
2,176 
2,180 
2,186 
2,195 

Lime  rock 

Gyp     gumbo       __. 

Blue  shale          

Blue  shale 

Hard  pink  shale 

Gyp     gumbo1 

Sand        -                

Sand  and  shale  streaks  

Hard  gummy  shale-.    _. 

Green  shale  and  boulders  

2,202 
2,240 
2,300 

Blue  shale  soft  and  gummy- 

Green  shale_-  -- 

Blue  and  pink  shale 

2,3€0 
2,405 

2,475 

Pink  shale 

Soft  lime  rock  

Gumbo 

2,476 
2,480 
2,500 
2,527 
2,540 
2,542 

Hard  shale  and  lime  streaks 
Not   recorded 

Sand    shale  

Sand  and  shale  streaks 

Dry  sand,  gas  show-  

Hard  sand  and  boulders  gas 
Hard  shale  and  shells 

show  

2,550 
2,562 
2,578 
2,588 
2,591 
2,603 
2,623 
2,630 
2,665 
2,689 
2,690 
2,709 
2,726 
2,746 
2,775 
2,802 
9  R07 

Gumbo 

Sand 

Pink  shale  and  boulders 

Hard  shale  and  sand  streaks 
Gumbo 

Hard   pink   gummy   shale  

Pink  and  blue  shale  

Rock   and  pyrites  _  ~      

Blue  slate  shale 

Soft  shale  and  sand  streaks 
Sulphur  water  sand  

Hard    sand                    

Soft  shale  and  sand  streaks 
Hard    sand 

Blue   shale  

Shale  and  boulders.—   .  

2,816       2,8591            43 

18 


University  of  Texas  Bulletin 


Log-  of  Breckenridg-e  No.  1,  South  Plains  Oil  &  Gas  Co.,  Survey  No.   460, 

Southeast  Corner  of  Block  15,  About  One  Mile 

Southwest  of  Mirando  City—Continued 


• 

Depth  i 

n  Feet. 

Thick- 

From. 

To. 

ness. 

Hard  sand  gas  showing  ...             _                     ' 

2  859 

2  879 

20 

Hard    sand  

2  879 

2  885 

g 

Hard  sand  gas  showing-  

2  885 

2  900 

15 

Hard   sand  

2  900 

2  928 

28 

Sulphud  water  sand  

2  928 

o  940 

1° 

Shale  and  boulders  

2,940 

2  980 

40 

Shale  and  gumbo  

2  960 

3  009 

29 

Log-  of  l-olts  No.  1,  Santa  Maria  de  los  Angeles  Surrey,  About  One-half 
Miles  East  of  Bruni,  In  Eastern  Fart  of  Webb  County 


From. 

To. 

ness. 

Soil   _.    __ 

0 

5 

5 

Sand  and  clay  

5 

10 

5 

10 

50 

40 

Hard   sand 

50 

75 

25 

Lime  rock 

75 

105 

30 

Gravel  and  water  sand  

105 

115 

10 

Sandy   shale  

115 

175 

60 

Water    sand 

175 

225 

50 

Hard  shale  

225 

325 

100 

Gumbo 

325 

400 

75 

Blue  shale  

400 

525 

125 

Water   sand  _ 

525 

625 

100 

Blue  shale  

625 

800 

175 

Gummy   red   shale 

800 

1  000 

20ft 

Blue  shale 

1  000 

1  100 

100 

Gummy  red  shale    

100 

1  200 

100 

Black  shale                   

,200 

1,300 

100 

Hard  blue  shale  

,300 

1,400 

100 

Gumbo 

400 

1  475 

75 

Hard  sandy   shale____________  ___________ 
Soft  blue  shale  

Gas  sand-         _     __     ___•__  ___    ___ 

,475 
,500 
600 

1,500 
1,600 
1  625 

25 
100 

25 

Hard  black  shale  _  

'_H-r 

1,700 

75 

Sea  shell 

1  700 

1  705 

5 

Sandy  shale  
Sea  shell     _     '.      '  I 

1,705 
1  790 

1,790 
1,800 

85 
10 

Soft  sandy  shale  __    _ 

1,800 

1,810 

10 

Depth  in  Feet. 


Casing  set  at  1,875  in  cement;  4%"  lines  set  at  1,650. 

Hole  was  bailed  dry,  making  quite  a  bit  of  gas;  pulled  lines  and  finished  hole  at 
1,810',  with  no  oil  showing. 


Notes  on  OH  and  Gas  Fields  of  Well)  and  Zapata  Counties    19 


Of  Xanola.  No.  l,  Survey  54,  About  One  and  One-half  Miles  South  of 
Uirautto   City.     After  Cleaning-  Well  Produced  80O  totals,  or 
More.      Discovery   Well   of   the    Schott    Pool 


Depth  in  Feet. 


From.      To. 


Thick- 
ness. 


Surface  soil 

Yellow  clay 

Soft  Time  clay 

Loose  gray  shale 

Red  and  blue  shale • 

Water  sand 

Fine  blue  sand — 

Red  mixed  shale 150 

Hard  red  clay 210 

Red  mixed  shale - 

Soft  lime  clay 

Red  mixed  shale -- 274  296 

Blue  shale ^ 296  320 

Gummy    shale 320 

Red  and  blue  shale 373 

Hard  gummy  shale 373 

Gumbo    399  411 

Soft  lime  rock 411  420 

Red  and  blue  shale 420  448 

Hard  lime  rock -  448  453 

Red  and  blue  shale. 453  512 

Hard  lime  rock 512 

Hard  blue  shale  and  lime —  522 

Hard  gummy  shale 601  622 

Lime  rock 622  635 

Red  and  blue  shale €35 

Lime   rock 660  672 

Hard  blue  shale 072 

Lime  rock 700  776 

Red  and  blue  shale 776  844 

Lime  rock 

Red  and  blue  shale__, 860  940 

Lime   rock — 940  978 

Red  and  blue  shale 978  1,000 

Lime  rock 1,000  1,023 

Red  and  blue  shale 1,023  1,073 

Gumbo    1,073  1, 

Lime  rock 1,084  1,102 

Gumbo    —  1,102  1,114 

Hard  gummy  shale 1,114  1,129 

Red  and  blue  shale __  1,129  1,140 

Lime   rock 1,140  1,162 

Hard  gummy  shale __, 1,162  1,184 

Gumbo,    1,184  l. 

Red  and  blue  shale _ 1,196  1,216 

Gumbo    1,216  1,227 

Lime   rock ^ 1,227  1,248 

Gummy  shale 1,248  1,271 

Lime  rock_ _.. . 1,271  1,282 

Gumbo    -  1,282  1,293 

Red  and  blue  shale ___  1,293  1,304 

Gumbo    - 1,304  1,313 

Lime  rock  and  shale 1,313  1,328 

Red  and  blue  shale 1,328  1,350 

Lime  rock — 1,350  1, 

Hard  blue  shale 1,362  1,374 

Red  and  blue  shale 1,374  1, 

Lime   rock 1,396  1,406 

Hard  blue  shale. — - 1,406  1,440 

Lime   rock 1,440  1,462 

Hard  blue  shale —  1,462  1,499 

Lime  rock  (gas  big) 1,499  1,508 

Hard  blue  shale 1,508  1,513 

Hard  lime  rock  (gray  sand)  set  casing  1515' 1,513  1,515 


20 


University  of  Texas  Bulletin 


tog-  of  Xanoka  No.  1,  Survey  54,  About  One  and  One-half  Miles  South  of 

MiraJido   City.     After  Cleaning1  Well  Produced  800  btols.  or 

More.    Discovery  Well  of  the  Schott  Pool — Continued 


•• 

Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Xiime   rock- 

1,515 
1,517 
1,522 
1,523 
1,533 
1,537 
1,543 
1,545 

1,517 
1,522 
1,523 
1,533 
1,537 
1,543 
1,545 
1,569 

2 
5 
1 
10 
4 
6 
2 
14 

Shells   and 
Sand   rock. 

shale__  _ 

Shale  and 
Gumbo    -— 

sand    - 

Shells   and 
Hard  lime 
Hard  sand 

shale  

rock  

(heavy  oil  sand)  

Stopped  in  gumbo. 
Set  casing"  in  cement. 
Set  6&,  7". 

Log-  of  Laredo  Oil  Co.,  Well  No.  1,  Survey  458,  in  Mirando  City 

Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Surface  _    . 

0 
10 
18 
20 
35 
45 
61 
62 
76 
86 
96 
101 
115 
133 
148 
179 
184 
194 
205 
213 
231 
246 
256 
284 
294 
304 
330 
344 
360 
375 
385 
393 
413 
414 
434 
454 
460 
480 
510 
525 
533 
555 

10 
18 
20 
35 
45 
61 
62 
76 
86 
96 
101 
115 
133 
148 
179 
184 
194 
205 
213 
231 
246 
256 
284 
294 
304 
330 
344 
360 
375 
\          385 
!          393 
413 
i          414 
434 
454 
460 
480 
510 
525 
533 
555 
587 

10 
8 
2 
15 
10 
16 
1 
14 
10 
10 

»! 

18 
15 
31 
5 
10 
11 
8 
18 
15 
10 
28 
10 
10 
26 
14 
16 
15 
10 
8 
20 
1 
20 
20 
6 
20 
30 
15 
8 
22 
32 

White  lime  and  sand  ...    ... 

Gravel   _ 

Sand    

•Clay'  _. 

Sand,   clay  and  shell  

Pink  shale  __       

".Red  clay  _i  __                      

-•Gray  shale  .       

Blue  and  gray  shale  _ 

White  lime  rock 

•Gray  shale 

Pink  gumbo 

Blue  snale 

(Gray  gumbo                                      

]Brown  shale 

Blue  shale               _  _       

Gray  shale           

Hard   shale 

Shale                                                                

Sandy   shale                    

Blue  gumbo                       -  

Brown  gumbo                    

Blue  gumbo                                    -  

ROCk                                                                                                                                                                                                      

Gray  shale                        

Grnv    erumbo  

Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties   21 


Log-  of  Laredo  Oil  Co.,  Well  No.  l,  Survey  458,  in  Mirando  City — Continued 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Slate  with  coal                             

587 
615 
654 
656 
664 
715 
759 
760 
778 
800 
816 
824 
825 
875 
883 
905 
920 
952 
960 
972 
978 
1,014 
1,029 
1,039 
1,049 
1,059 
1,076 
1,084 
1,089 
1,092 
1,114 
1,146 
1,165 
1,185 
1,215 
1,230 
1,260 
1,275 
1,285 
1,291 
1,321 
1,341 
1,411 
1,431 
1,446 
1,466 
1,496 
1,521 
1,531 
1,56] 
1,581 
1,621 
1,6& 
1,«6C 
1,654 
1,665 

615 

654 
656 
664 
715 
759 
760 
778 
800 
816 
824 
825 
875 
883 
905 
920 
952 
960 
972 

28 
39 
2 
8 
51 
44 
1 
18 
22 
16 
8 
1 
50 
8 
22 
15 
32 
8 
12 
6 
86 
15 
10 
10 
10 
17 
8 
5 

22 
32 
19 
20 
30 
15 
30 
15 
10 
6 
30 
20 
70 
20 
15 
20 
30 
25 
10 
30 
20 
40 
15 
14 
4 
•  8 

Rock                                                         _               

White  lime  rock                                                       -    ---    

day  shale                                                -          --  

Rock                                               _         

Gray  shale                                                                    -    -  -      - 

Brown   shale                                                --      -                -  

978 
1,014 
1,029 
1,039 
1,049 
1,059 
1,076 
1,084 
1,089 
1,092 
1,114 
1,146 
1,165 
1,185 
1,215 
1,230 
1,260 
1,275 
1,285 
1,291 
1,321 
1,341 
1,411 
1,431 
1,44€ 
1,4« 
1,49* 
1,521 
1,531 
1,561 
1,58] 
1,62] 
1,63( 

i,ea 

1,65^ 
1,661 

Blue  shale                                                       -    -      

Blue  gumbo                                                   -  

Blue  gumbo                                                                  -    

Shale                                                       -    

Lime   rock                                -                    

Shale  and  gumbo                                                      --       -- 

Shale                                             

Soft  lime  rock                                                     

•Gumbo                                                                                                

Blue  shale                                          -  -               

Shale                                                       

Gumbo                            

Shale                           -    --    

<§hale                                             -          

Shale                                   

Rock                              --  -  —  - 

This  well  gave  a  flow  of  oil  when  first  drilled.     Subsequently  abandoned  on  account 
of  water  trouble. 


22 


University  of  Texas  Bulletin 


log-  of  Well  On  Reiser  Hanch,  Producers  Oil  Co.,  B.  &  M.  Lease  Well  No.  5r 

Survey  1617,  About  One-fourth  Mile  South  of  Reiser's 

Station.     Total  Depth  2,598 


s  

Depth  j 

n  Feet. 

Thick 

From. 

To. 

ness. 

Surface  sand  

0 

3 

3 

Sandy  red  clay 

3 

g 

3 

Brown   sand  __      __ 

6 

12 

6 

Gravel  with  some  salty  water     

12 

14 

o 

Brown   shale  __       

14 

45 

31 

Sandy  yellow  clay  

45 

58 

13 

Brown   shale 

58 

110 

59 

Sand 

110 

118 

8 

Shale 

118 

126 

g 

Shale 

126 

164 

35 

Gumbo 

164 

170 

6 

Shale    

170 

208 

38 

Lime  shells  with  some  sand  

208 

220 

12 

Red  clay  __ 

220 

286 

63 

Sand  salt  water 

286 

992 

6 

Shale  black 

292 

334 

4-> 

Sand 

334 

339 

5 

Sandy  shale 

339 

404 

65* 

Gumbo     

404 

413 

9 

Shale  black  

413 

476 

(>3 

Sand    

476 

482 

G 

Shale    

482 

564 

82 

Gumbo    

564 

570 

6 

Brown   shale 

570 

642 

79 

Sand,  gas  show 

642 

649 

y 

Black   shale 

fi49 

674 

25 

Gumbo 

674 

686 

12 

Red  clay 

686 

793 

107" 

Sand 

79S 

798 

5 

Shale  with  sand  shell                 .            —             —    ._    — 

798 

885 

87 

Sandy  shale             -    _  _    ____       

885 

914 

29 

Gray  salt  sand 

914 

926 

12 

Brown   shale  

926 

938 

12 

Sand    

938 

945 

Shale  with  sand 

945 

987 

49 

Sandy   shale    -- 

987 

1,032 

45 

Blue  shale    sand  shells,  iron 

1,032 

1,116 

84 

Gumbo                                             -    - 

1,116 

1,123 

7 

Sand 

1,123 

1,138 

15 

Sandy  blue  shale                    J_      

1,138 

1,184 

46 

Sand                              -      --            -    --    —  

1,184 

1,192 

8 

Black   shale           _         _.    _  

1,192 

1,203 

16 

Sand 

1,208 

1,227 

19 

1,227 

1,243 

21 

1,248 

1,285 

37 

1,285 

1,312 

27 

Shale                             

1,312 

1,324 

12 

Sand                          

1,324 

1,332 

8 

Sand     set  8"                                             

1,332 

1,369 

37" 

This  well  is  said  to  have  been  subsequently  drilled  to  a  depth  of  2,598  feet.     Water- 
was  obtained  at  about  1,800  feet,  and  gasi  is  reported  at  about  2,500  feet. 


Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties   23 


Log-  of  Garcia  No.  2,  Schott  Oil  Co.,  Survey  54,  About  One   and  One-half 

Miles  South  of  Mirando  City.     Gas  and  Oil  Well,  Initial 

Production  Oil  Reported  at  74  tobls. 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Yellow   sand 

0 
2 
10 
30 
57 
107 
135 
168 
165 
220 
260 
290 
330 
342 
475 
490 
587 
563 
600 
637 
670 
673 
€&5 
687 
700 
745 
750 
800 
805 
861 
873 
897 
900 
918 
937 
960 
968 
1,000 
1,020 
1,067 
1,083 
1,100 
1,115 
1,160 
1,187 
1,193 
1,213 
1,237 
1,275 
1,297 
1,317 
1,350 
1,357 
1,384 
1,400 
1,410 
1,427 
1,449 
1,467 
1,482 
1,500 
1,510 
1,515 
1..523 
1,527 
1,530 

2 

10 
30 
57 
107 
135 
163 
165 
220 
260 
290 
330 
342 
475 
490 
537 
563 
600 
637 
670 
673 
685 
687 
700 
745 
750 
800 
805 
861 
873 
897 
900 
918 
937 
960 
983 
1,000 
1,020 
1,067 
1,083 
1,100 
1,115 
1,160 
1,187 
1,193 
1,213 
1,237 
1,275 
1,297 
1,317 
1,350 
1,357 
1,384 
1,400 
1,410 
1,427 
1,449 
1,467 
1,482 
1,500 
1,510 
1,515 
1,523 
1,527 
1,530 
1,532 

2 
8 
20 
27 
50 
28 
28 
2 
55 
40 
30 
40 
12 
138 
15 
47 
26 
37 
37 
33 
3 
12 
2 
13 
45 
5 
50 
5 
56 
12 
24 
3 
18 
19 
28 
23 
17 
20 
47 
16 
17 
15 
45 
27 
6 
20 
24 
38 
22 
20 
33 
7 
27 
16 
10 
17 
22 
18 
15 
18 
10 
5 
8 
4 
3 
2 

Soft  limA  clay                                       --       --       - 

Yellow  clay 

Blue   shale 

R£d   clay                                              

Soft  lime  rock 

Hard  blue  shale 

Lime  rock 

Hard  blue  shale 

Blue  shale  and  sand 

Gumbo                                                                           

Blue  shale                          __      _                 ._       

Red  and  blue  shale 

Blue  shale  and  sand 

Soft  lime  rock 

Hard  blue  shale  and  sand 

Lime  rock--      _  --  

Tough    gumbo 

Lime  rock 

Gumbo 

Lime  rock       _               _-    __          __       

Gumbo 

Lime  rock 

Gumbo                                                  -    -  

Hard  blue  shale       __       

Lime  rock 

Red  and  blue  shale 

Soft  lime  rock                                 -_       _         

R«d  and  blue  shale       

Lime  rock__      

Gumbo 

Blue  shale 

Lime  rock 

Gumbo    -_  

Blue  shale  and  sand 

Tough   gumbo 

Soft  rock  _    —      __    

Hard  blue  shale 

Gumbo 

Lime  rock 

Red   and  blue  shale  __ 

Gumbo 

Lime  rock 

Hard  blue  shale  -    

Lime  rock__          .  

Hard  blue  shale 

Gumbo 

Lime   rock  _              _    __    

Gumbo   _.    _ 

Hard  blue  shale 

Lime  rock 

Gumbo    -    

Hard  blue  shale—      

Lime  rock 

Blue    shale 

Soft  blue  mud 

Soft  lime  rock 

Red  and  blue  shale    

Soft  lime  rock  „    

Hard  lime  rock 

Tough   gumbo 

Hard  lime  rock-  

Soft  lime  rock 

Hard  lime  rock 

Hard  blue  reck,  sandstone  __    

Porous  gray  sand  rock 

University  of  Texas  Bulletin 


Log-  of  Urban  No.  1,  Bio  Grande  Oil  &  Gas  Co.,  Survey  7;  Ten  or  Twelve 

Miles   North   of   Laredo 


Depth  i 

n  Feet. 

Th  ick- 

Prom. 

To. 

ness. 

Yellow  clay  

0 

18 

118 

White   shale 

18 

30 

12 

Blue  shale 

30 

30 

Pink  shale  _       -  __ 

60 

80 

20 

Sand 

80 

Of) 

10 

Blue  shale 

90 

260 

170 

Cave  __    

260 

265 

5 

Blue  shale 

265 

290 

25 

Cave  _            —       

290 

295 

5 

Blue  shale 

295 

360 

65 

Cave                       

360 

365 

5 

Blue  shale  _    _            

365 

545 

180 

Sand,   showing  of  oil 

545 

553 

8 

Blue  shale  . 

553 

633 

80 

Slate 

633 

800 

167 

Water  sand 

800 

881 

81 

Shale             

881 

860 

70 

Sand 

960 

1  000 

40 

Slate       _.    

1  000 

1  006 

(j 

Sand         

1,006 

1,058 

52 

Slate 

1  058 

1  075 

17 

Sand               _          -    

1  075 

1,093 

18 

Water  sand 

1  033 

1  103 

10 

Slate 

1  103 

1  122 

19 

Sand                                    

1,122 

1,140 

19 

Slate  -          —    — 

1,140 

1,145 

Sand 

1  145 

1  ?10 

65 

Slate        

1,910 

1,220 

10 

Sand  

1,220 

1  255 

35 

Slate 

1  255 

1  263 

g 

Sand                           -    

1  263 

1,320 

57 

Sand  _-    _    _-         

1,320 

1,340 

2o 

Water*  sand 

1,340 

1,366 

25 

Brown  shale             

1,365 

1,369 

4 

Sand  

1,369 

1,400 

31 

Slate 

1,400 

1,404 

4 

Sand     began  underreaming'  1,130' 

1  404 

1,450 

46 

Red    rock 

1,450 

1  455 

Sand                      --          

1,455 

1  470 

15 

Red   rock  i  __ 

1,470 

1,472 

2 

Sand 

1  472 

1,515 

43 

Broken  formation,  sand,  slate,  red  rock  _ 

1,515 

1,580 

65 

Sand 

1  580 

1  600 

9Q 

Casing  record:     Set  12y2",  casing  at  553';  10"  at  1,058'. 

Log  Wells  in  Zapaita  County 

Log-    of    Hinnant    No.    6,    Mirando    Oil    Co.,    Survey    114,    Block    5,    Lot    1, 
Initial  Production  150  btols.,  Mirando  Pool 


Depth  i 

n  Feet. 

Thick- 

Prom. 

To. 

ness. 

Clay  and  gravel 

0 

98 

93 

Pack  sand 

98 

100 

2 

Blue   shale                                               -  

100 

140 

40 

Hard  shale 

140 

150 

10 

Shale  and  sand                                                        

150 

170 

20 

Shale 

170 

360 

190 

Boulders  _.        

360 

371 

n 

Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties   25 


of    Hinnant    No.    6,    Mirando    Oil    Co.,    Survey    114,    Block    5,    Lot    1, 
initial  Production   15CKJ  bbls.,  Mirando   Pool — Continued 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Shale 

371 
590 
600 
638 
641 
658 
665 
720 
725 
815 
826 
857 
860 
863 
1,040 
1,059 
1,099 
1,108 
1,123 
1,167 
1,231 
1,257 
1,320 
1,384 
1,401 
1,412 
1,425 
1,431 
1,448 
1,462 

590 
600 
638 
641 
658 
665 
720 
725 
815 
826 
857 
860 
863 
1,040 
1,059 
1,099 
1,108 
1,123 
1,167 
1,231 
1,257 
1,320 
1,384 
1,401 
1,412 
1,425 
1,431 
1,448 
1,462 
1,467 

219 
10 
38 
3 
17 
7 
53 
5 
90 
11 
31 
3 
3 
177 
19 
40 
9 
15 
44 
64 
26 
63 
64 
17 

3 

6 
17 
14 

5 

Gumbo          

Shale 

Sandy  shale 

Shale 

Boulders                                            a 

Shale    

Boulders 

Hard  sandy  shale  _    .                 

Hard  red  gumbo  

Hard   shale 

Rock 

Shale       _         __    _—      -.          _  

Hard  shale  and  boulders 

Green  gumbo_  

Hard  shale 

Green  gumbo-                   -_    _                 

Hard  shale  and  boulders  

Blue   shale 

Hard  shale  boulders  _  _ 

Stiff  blue  gumbo  

Hard  shale 

Shale  and  boulders 

Hard  shale 

Green  gumbo 

Pay  shale  and  sand    

Gumbo    

Hard  shale 

Pay  sand  and  shale                                    _ 

Boulders                -—  -- 

Log-    of    Hinnant    No.    7,    Mirando    Oil    Co.,    Survey   307,    Block    17,    Lot    4, 
Completed  November  26,  1921,  Mirando  Pool 


Depth  i 

n  Feet. 

Th  i>lr 

From. 

To. 

ness. 

Clay  and  gravel 

o 

12 

12 

Mixed  shale 

12 

48 

33 

Hard  sandy  shale          

48 

65 

17 

Mixed    shale         _    t  

65 

182 

117 

Hard   shale 

182 

220 

33 

Hard  shale  and  boulder  r  *_ 

220 

273 

53 

Hard    sand 

273 

275 

2 

Sandy  shale                                            _  «    __ 

275 

348 

73 

Hard  sand  and!  boulder 

348 

362 

14 

Rock 

362 

365 

3 

Hard  shale 

365 

385 

20 

Hard   sand                                    _    _    _         ____ 

385 

387 

2 

Sandy  shale 

387 

501 

114 

Hard  shale                            ^-             __               .... 

501 

545 

44 

545 

567 

22 

Hard  shale 

567 

587 

20 

Hard  shal8  and  boulder 

587 

704 

117 

Gumbo 

704 

710 

c 

Hard  shale  and  boulder—  -  —  -  -    _——-__——-  -  - 

710 

760 

50 

760 

778 

18 

Hard  shale  and!  boulder 

778 

840 

62 

Gumbo  and  boulder                       —  -    ____             _  __ 

840 

865 

25 

865 

906 

41 

Hard  shale                „    

906 

956 

50 

Gumbo 

950 

991 

35 

26 


University  of  Texas  Bulletin 


of    Hinnant    No.    7,   Mirando    Oil    Co.,    Survey    307,    Block    17,    lot    4, 
Completed  November  26,  1921,  Mirando  Fool — Continued 


Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Hard  shale  and  boulder  __ 

991 
,030 
,034 
,040 
,071 
,081 
,166 
,180 
,252 
1,290 
1,S62 
1,392 
1,403 
1,446 
1,470 
1.476 

1,030 
1,034 
1,040 
,071 
,081 
,165 
,180 
,252 
1,290 
1,362 
1,392 
1,403 
1,446 
1,470 
1,476 
1.490 

39 
4 
6 
31 
10 
84 
15 
72 
38 
72 
30 
11 
43 
24 
6 
14 

Hard  shale  and  boulder-- 

Gumbo     __ 

Hard  shale  and  boulder..  

Boulder   

Hard  shale 

Gumbo    __    -_             

Hard  shale  and  boulder 

Gumbo  and  boulder  

Hard  shale  and!  boulder 

Hard  shale 

Gumbo   

Shale 

Gumbo    _    

Hard   sand 

Shale   _. 

Casing  record: 


>';  initial  production  reported  at  100  bbls. 


Log-  of  Hinnant  No.  3,  Witherspoon  Oil  Co.,  Surtfey  115,  Block  3, 
Mirando  Pool 


Depth  i 

n  Feet. 

Thick- 

From. 

To. 

ness. 

Red  clay  and  gravel 

0 

60 

60 

Soft   shale 

60 

186 

126 

Shale  and  boulders 

186 

336 

150 

Loose   shale 

336 

520 

184 

Shale  and  boulders  __       

520 

620 

100 

Gumbo 

620 

25 

Hard   gumbo 

645 

655 

10 

Shale  and  boulders                  _             _  ._ 

655 

710 

55 

Gumbo            .              --    -    

710 

720 

10 

Hard   gumbo  !  

720 

760 

40 

Gumbo  and  gravel 

760 

810 

50 

Hard   gumbo                                       

810 

840 

30 

Pink  shale                                                —    

840 

900 

60 

Gumbo                 -  

900 

920 

20 

Shale 

920 

940 

20 

Hard   gumbo 

940 

980 

40 

Gumbo                                                          -            

980 

995 

15 

Pink   shale                      —                                *-_  

995 

55 

Hard  sand  and  boulders 

1,050 

1*070 

20 

Shale  anl  boulders                                            -    --    —    -—  —  

1,070 

1*100 

30 

Gumbo  and  shale                                        -      

1,100 

I,'l50 

50 

Hard  gumbo                            -         -    

1,150 

50 

Shale                                             

1,200 

1,220 

20 

1,220 

1  260 

40 

1,260 

1,320 

60 

Hard  sand   and  boulders                       

1,320 

30 

1,350 

1,360 

10 

Sand  and  shale                                                                     -    

1,360 

1,364 

4 

1,364 

4 

Shale                                              -  

1,368 

1,375 

7 

1,375 

1,390 

15 

Soft'   shale                        --      -    

1,390 

1,435 

45 

Hard  sand     oil  showing                 --  -  -- 

1,435 

1,440 

5 

Shale  and  sand—- 

1,440 

1,490 

50 

Reported  producing  90  bbls.  per  day  in  April,  1922. 


Notes  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    27 


Log-    of 


[innant   No.   4,   Witherspoon   Oil    Co.,    Survey   307,   Block    18, 
Mirando   Fool;   Well  Abandoned 


Depth  i 

n  Feet. 

Th  if»lr 

From. 

To. 

ness. 

Red  clay  and  gravel  

0 

60 

60 

Shale   .__      

60 

180 

120 

Shale  and  boulders  _  _ 

180 

400 

220 

Gumbo 

400 

460 

60 

Gumbo  and  particles  of  iron 

400 

520 

60 

Boulders  and  shale  

520 

600 

30 

Gumbo   

600 

680 

80 

Shale  and,  boulders  

680 

760 

80 

Sand   rock  _         

760 

770 

10 

Hard'  gumbo  _ 

770 

820 

50 

Hard  sandy  shale  

820 

860 

40 

Sand  and  boulders  

860 

900 

40 

Hard   gumbo.  

900 

940 

40 

Shale  and  boulders  

940 

1  110 

170 

Hard  shale 

1  110 

1  140 

30 

Boulders  and  gumbo 

1  140 

1  220 

80 

Shale  and  boulders-. 

1  220 

1  250 

30 

Gumbo    __ 

1  250 

1  260 

10 

Shale  and  sand  upper  pay 

1  260 

1  380 

120 

Hard  gumbo  and  sand  

1,380 

1,435 

55 

Soft  shale  andi  sand  

1,435 

1,445 

10 

Hard  brown  gumbo 

1  445 

1  450 

5 

Hard   gumbo 

1  450 

1  490 

40 

Sand    _. 

1,490 

1,500 

10 

Gumbo    

1  500 

1  563 

63 

Rock    

1  563 

1  565 

2 

Hard   gumbo  _    _.    _ 

1  565 

1,600 

35 

Sand  __ 

1,600 

1  610 

10 

Gumbo 

1  610 

1  690 

89 

Rock    

1  690 

1  692 

2 

Sandy   shale  

1  692 

1,700 

3 

Not   reeoTded 

1  700 

1  735 

35 

Hard  sand  rock 

1  735 

2*000 

265 

Log-  of  Slator  No.  1,  Producers  Oil  Co.,  Jose  Boreffo  Vosquez  Grant,  Within 
About  a  Mile   of   North   County   Line;  Elevation  595 


Depth  ] 

n  Feet. 

ThiW 

From. 

To. 

ness. 

Soil 

0 

45 

45 

Shale 

45 

65 

20 

Sandy  shale 

65 

84 

19 

Black  shale          _            

84 

208 

124 

Gumbo    _- 

208 

221 

13 

Sand 

221 

230 

g 

Shale 

230 

345 

115 

'Gumbo                                                  --    

345 

395 

50 

Shale                                  _ 

395 

507 

112 

•Sand  

507 

512 

5 

:  Shale 

512 

691 

179 

691 

720 

29 

"Shale  with  iron 

720 

814 

94 

Rock     white 

814 

820 

Q 

:Shale,   black                                        

820 

104 

284 

:Sand                                           .    

1,104 

,106 

2 

Black  shale 

1  106 

116 

10 

:Sand 

1  116 

119 

3 

'Shale 

1  119 

291 

172 

1,291 

400 

109 

Bluo  shale  

1,400 

1,419 

19 

Sand  -. 

1.419 

1.424 

5 

28 


University  of  Texas  Bulletin 


Log1  of  Slator  No.  1,  Producers  Oil  Co.,  Jose  Boreso  Vosquez  Grant,  Withiir 
About  a  Mile  of  Nrth  County  Line:  Elevation  596 — Continued 


1 

Depth  in  Feet. 

Thick- 
ness. 

From. 

To. 

Shale                                        —                                    .                         ! 

1,424 
1,443 
1,400 
1,493 
1,503 
1,508 
1,527 
1,557 
1,563 
1,580 
1,588 
1,612 
1,649 
1,747 
1,750 
1,791 
1,895 
1,902 
1,920 
1,925 
1,964 
1,984 
2,020 
2,107 
2,194 
2,195 

j 

1,443             19- 
1,460             17 

1,493         33 

1,503             10 
1,508'              5 
1,527             19 
1,551             30 
1,563               6 
1,580             17 
1,588              8- 
1,612             24, 
1,649             37 
1,747             98, 
1,759             12 
1,791             38 
1,805           104 
1,902              7 
1,920             18 
1,925'              5 
l,964i            39 
1,984             20 
2,020             36 
2,107i            87 
2,194j           87 
2,195!              1 
j      2,210!            15 

Shale  and  sand  _      

Sand  and  iron..    

Shale   _      —    

Bock   and  sand 

Shale                                              _    . 

Bock  sand  and  iron  (show  gas  1,582-1,540)  

Sulphur  water,    sand 

Sand  and  iron                                    —    .            -    

Shale                       

Flinty  rock  and!  sand 

Shelly    shale 

Sand  and  iron               -    -    --  -  -  -  

Shale                                                           _                      

Shells   and  pyrite 

Sha.le 

Lime  rock                                                                -  -       --  

Shelly    shale 

Lime  shell 

Shelly    shale 

Slate                                                                        —           

Shelly    shale                  

Shale  and  slate 

Shale     sandy 

Sand 

Shale,   sandy                   -     —  -  - 

Log-  of  Zapata  Oil  &  Gas  Co.,  in  ciiarco    Redondo  Field,  Southeast  Fart  of 
Zapata    County,    Yellow    Clay   and   Sand 

Depth  i 

n  Feet. 

Thick- 

From. 

To. 

ness. 

Yellow  clay  and  sand 

0 

18 

18- 

Light   green   clay 

18 

70 

52 

Blue  and  green   shale    __  _  

70 

78 

8 

Boulders  and  slate 

78 

83 

5 

Blue  clay   and  slate 

83 

163 

80 

Oil  sand 

163 

168 

5 

Shells,    fossil   oysters             

168 

169 

1 

Clay   and  shale 

169 

194 

25 

Light  blue  clay 

194 

240 

46 

Shale  and  fossil  shells                         -  -_ 

240 

258 

18 

958 

<T1 

13 

Shells   and  shale 

271 

283 

12 

Bed  clay 

283 

307 

24' 

Clay     thin  sand  strata                                  -       - 

307 

323 

16- 

White   clay 

323 

362 

39 

Bed  clay 

362 

381 

19 

Green    shale 

381 

390 

9" 

H^ird  green  shale                                                                   -    

390 

438 

4b 

Shell   and  shale                __                  

438 

443 

5- 

Shells  and  shales 

443 

610 

167 

Sand  and  shale                                                      -               - 

610 

619 

^ 

Green  andl  blue  shale                     -    -  -—  -      —  —  

619 

648 

29 

648 

662 

14 

Bed  and  green  shales                                               —  -  -  - 

662 

714 

52 

Shells   and  shale                                                —  -    ____________ 

714 

760 

46 

Tough  gumbo                       —  

760 

769 

9 

769 

783 

14 

Hard  slaty  shale                                             _                         

783 

789 

6 

Gumbo    -          —  -  ...                                                                  

789 

803 

14 

Xotcs  on  Oil  and  Gas  Fields  of  Webb  and  Zapata  Counties    29 

3-  of  Zapata  Oil  &  Gas  Co.,  in  Charco  Redondo  Field,  Southeast  Part  of 
Papata   County,   Yellow   Clay   and   Sand— Continued 


' 
Depth  in  Feet. 

Thick- 
ness. 

From.      To. 

Hard  shale  and  boulders 
Shale  and  soft  slate 

803          807 
807|          826 
826           841 
841           848 
848           860 
860           932 
932           965 
965!          992 
992|         998 
998J      1,037 
1,037       1,043 
1,043       1,069 
1,069!       1,078 
1,078!      1,118 
l,118i       1,130 
1,130;       1,150 
1,150       1,172 
1,172       1,175 
1,175       1,226 
1,226       1,238 
l,238j      1,247 
1,247       1,263 
1,263       1,270 
1,270!       1,286 
1,286       1,298 
1,298       1,302 
1,302|      1,308 
-  1,3081      1,329 
1,329       1,341 
1,341       1,347 
1,347       1,5:63 
1,862:       1,268 

4 
19 
15 
,  7 
12 
72 
33 
27 

6 
26 
9 
40 
12 
20 
22 

A 

12 

9 
16 
7 
16 
12 
4 
6 
21 
12 
6 
15 
6 
17 
12 
29 
22 
14 
!           17 
18 

5 

2 
11 

8 
7 
29 
23 
26 
10 
i            21 
6 
1             12 

1             15 
14 
15 
5 

I 

!j            11 

Dull  brown  gumb  o* 

Hard  sand  and  shells 

Shale,  shells  and  concret 
Shale 

ons  _    _       -    -         

Sand  and  boulders,  gas 
Blue  shale 

bubbles 

Sand  and  shale    pyrite 

Shale 

Light  green  clay 

Dark    shale    _ 

Gumbo    - 

Blue  shale 

Sand  and  green  shale 

Hard  sandstone 

Sand  and  shale 

Harrl  ga.nd,<?trmA 

Shale  and  gumbo       

Sha.le  and  sandstone 

Gumbo    _    _    

Shale  and  shells 

Black  shale  and  pyrite 

Clay 

Hard   dark,  shale 

Sand  and  shale 

Hard   sandstone 

Shale 

Shale  and  gumbo  

Hard   rock  . 

Shale  and  slate__    

Shells  —    

Soft  white  clay 

1,368       1,385 
1,385       1,397 
1,397       1,426 
1,426       1,448 
1,448       1,462 
1,4621      1,479 
1,479       1,497 
l,497j       1,501 
1,501        1,506 
1,506       1,508 
1,508       1,519 
1,519       1,524 
1,524       1,531 
1,531       1,560 
1,560       1,583 
1,583       1,609 
1,609       1,618 
1,619       1,640 
1,640       1,646 
1,646        1,655 
1,658       1,673 
1,673       1,687 
1,687       1,702 
1,702       1,707 
1,707       1,712 
1,712       1,717 
1,717       1,725 
1,728       I,7ffl5 

Shale  and  slate.  _      . 

Black  shale  and  shells 

Clay     with  shells 

Shell   rock   gypsum 

Shale  and  shells 

Sand  and  shale 

Soft  white  clay          __  _ 

Hard   rock  concretions 

Shale    

Rock       

* 

Soft  white  clay 

Rocks 

Shale--  and   clay 

Shale  and  shells    - 

Clay  and  boulders—  

White   clay 

Shales  and  clay  

Rock   slaty.      

Rocks,   concretions   and 
Sandstone 

gypsum 

White  clay  boulders 

Shells    and   concretions  

Sandstone  slate 

Rock    pyrite 

Gumbo 

Sandstone 

Shale  and  sand 

30  University  of  Texas  Bulletin 


THE  UNDERGROUND  POSITION  OF  THE  AUSTIN 
FORMATION  IN  THE  SAN  ANTONIO  OIL  FIELDS 

BY  E.  H.  SELLARDS 

The  Austin  formation,  or  Austin  chalk,  underlies  all  of  the 
oil  fields  of  the  San  Antonio  district,  and  is  itself  productive 
of  oil  in  the  Alta  Vista  and  Mission  fields  and  perhaps  to  a 
lesser  extent  elsewhere.  It  is  a  thick  formation,  varying  from 
possibly  three  hundred  and  fifty  to  four  hundred  and  fifty 
feet  or  more,  consisting1  of  a  chalky,  usually  light  colored  or 
blue  rock,  and  with  the  possible  exception  of  the  Eagleford, 
which  lies  next  below  it.  is  the  most  readily  indentifiable  for- 
mation of  the  Upper  Cretaceous  series.  For  this  reason  it  is 
perhaps  the  most  serviceable  of  the  Upper  Cretaceous  forma- 
tions in  deciphering  structural  conditions  from  well  records. 
It  is  true  that  the  transition  from  the  overlying  Taylor  to  the 
Austin  is  gradual,  and  that  there  is  probably  a  lack  of  uniform- 
ity on  the  part  of  drillers  in  recognizing  the  top  surface  of 
the  chalk.  However,  such  inconsistencies  as  arise  from  this 
cause,  although  of  importance  in  detailed  mapping,  probably 
do  not  materially  affect  the  accuracy  or  records  when  used 
in  mapping  general  or  regional  structures. 

The  well  records  here  used  are  those  of  the  Bureau  of  Eco- 
nomic Geology  of  the  University  of  Texas,  and  include  many 
records  contributed  or  made  available  by  several  oil  companies 
and  individuals. 

In  Bexar  County,  the  Austin  is  found  at  the  surface  in  a 
belt  of  country  extending  through  the  county  in  a  northeast- 
southwest  direction  and  passing  near,  but  mostly  north  of  San 
Antonio.  At  its  northwest  margin  this  belt  of  Austin  exposures 
is  marked  by  a  more  or  less  well  defined  west-facing  escarp- 
ment. Beyond  this  escarpment  to  the  northwest,  the  Austin 
is  wanting,  and  the  formations  at  the  surface,  with  the  excep- 
tion of  the  Eagleford,  are  of  Lower  Cretaceous  age.  On  the' 
other  hand,  to  the  southeast  the  Austin  passes  underneath 
later  formations  and  is  found,  as  stated,  underlying  the  oil  fields. 


Underground  Position  of  Austin  Formation  in  Oil  Fields     31 

While  the  Austin  passes  below  the  surface  to  the  southeast, 
the  rate  per  mile  at  which  it  drops  to  a  lower  level  is  by  no 
means  uniform.  On  the  contrary  it  is  found  from  well  records 
that  while,  in  places,  the  formation  drops  very  abruptly  to  a 
lower  level,  elsewhere  it  again  rises  towards  the  surface,  result- 
ing in  alternately  structurally  high  and  low  areas. 

To  the  southeast  of  the  Alta  Vista  and  Somerset  fields,  the 
Austin  evidently  drops  to  a  lower  level  very  rapidly,  although 
there  may  of  course  be  as  yet  undetected  interruptions  or 
reversals  in  the  dip.  That  the  average  rate  of  descent  of  thp 
Austin  is  rapid,  however,  is  demonstrated  by  the  fact  that  the 
formation,  unless  greatly  altered  in  character,  was  not  reached 
in  the  Richter  well  near  Pleasanton,  about  twenty  miles  south 
of  the  Alta  Vista  field  although  drilling  Avas  continued  to  a  depth 
of  4015  feet,  or  to  a  level  of  about  3665  feet  below  sea  level. 

In  the  northwestern  part  of  Atascosa  County  the  Austin  for- 
mation lies  at  a  depth  of  1700  or  1800  feet.  The  drop  to  the 
Richter  well,  allowing  for  difference  in  elevation,  amounts  to 
not  less  than  2500  or  2600  feet  in  fifteen  miles.  The  average 
rate  of  descent  in  the  formation  crossing  Atascosa  County  in 
a  southeasterly  direction  is  therefore  not  less  than  an  average 
of  165  or  175  feet  per  mile. 

In  referring  to  the  underground  position  of  the  Austin  chalk 
it  is  of  course  understood  that  this  formation  is  but  one  of  a 
series  of  formations  lying  in  natural  order,  the  one  upon  the 
other,  and  that  where  the  records  are  such  as  to  indicate  that 
one  of  the  formations  lies  at  a  relatively  high  elevation  it  may 
be  with  confidence  concluded  that  the  other  formations  of  the 
same  series,  when  not  separated  by  an  unconformity,  likewise 
lie  at  a  relatively  high  level  at  that  locality.  In  this  way  a 
certain  formation  recognizable  in  well  logs  may  be  used  in 
determining  structural  conditions,  regardless  of  whether  the 
formation  itself  is  productive  or  not,  and  from  structural  con- 
ditions in  turn  may  be  inferred  to  some  extent  the  probability 
of  oil  production  in  that  particular  locality.  Accordingly  the 
Austin,  for  the  reasons  given,  is  here  used  in  depicting  the 
structural  conditions  in  this  region  so  far  as  these  conditions 


32  University  of  Texas  Bulletin 

can  be  shown  on  a  small  map  and  from  wells  that  are  in 
some  parts  of  the  area  much  fewer  in  number  than  could  have 
been  desired. 

General  Structural  Conditions  in  the  San  Antonio  District 

No  more  than  brief  reference  will  be  made  at  this  time  to 
the  general  structural  conditions  in  the  San  Antonio  district, 
these  conditions  having  been  somewhat  fully  described  else- 
where. The  Balcones  zone  of  folding  and  faulting,  as  is  well 
known,  passes  through  this  district.  The  inner  margin  of  this 
fault  zone  (inner  in  the  sense  of  farthest  inland  from  the  Gulf) 
is  marked  in  this  part  of  the  State  by  a  pronounced  south- 
east facing  escarpment,  the  trend  of  the  fault  zone  being  north- 
east-southwest. Beyond  the  escarpment  to  the  northwest  the 
formations,  which  are  those  of  the  Lower  Cretaceous,  are  but 
little  disturbed  by  faulting  and  have  a  very  moderate  and 
scarcely  perceptible  dip  towards  the  Gulf.  To  the  southeast 
of  this  escarpment,  on  the  other  hand,  is  a  region  of  profound 
disturbance,  th$  formations  being  both  faulted  and  folded. 
This  disturbed  zone  is  known  to  be  more  than  twenty  miles  in 
width  and  it  may  be  much  wider.  The  faults  observed  are 
normal  or  tension  faults,  the  downthrow  being  in  the  direc- 
tion of  the  dip  of  the  fault  plane.  In  most  of  the  faults  the 
downthrow  is  to  the  southeast.  This,  however,  is  not  invariable 
as  faults  are  seen  at  the  surface  and  recognized  in  well  drill- 
ing in  which  the  downthrow  is  in  the  opposite  direction  or  to 
the  northwest.  In  that  case  the  dip  of  the  fault  plane,  where 
observed,  is  likewise  to  the  northwest.  The  faults  with  down- 
throw to  the  southeast  exceed  in  number,  as  already  stated, 
those  with  downthrow  to  the  northwest;  they  likewise  in  gen- 
eral exceed  in  intensity  or  in  amount  of  throw.  Moreover  the 
regional  dip  is  to  the  southeast  and  while  there  are  reversals 
of  dip,  these  are  seldom  continued  for  any  great  distance.  The 
ultimate  result  of  faulting  and  folding  in  this  zone  is  to  carry 
the  formations  very  rapidly  to  a  lower  level.  When  averaged 
across  the  county  from  the  Balcones  Escarpment  to  the  eastern 
part  of  Bexar  County  the  rate  of  drop  in  the  formations  will 


Underground  Position  of  Austin  Formation  in  Oil  Fields     33 

be  found  to  fall  between  100  and  150  feet  per  mile,  probably 
a  close  approximation  to  125  feet  per  mile.  But  that  such  an 
average  rate  of  descent  can  be  applied  only  in  the  most  gen- 
eral way,  becomes  apparent  from  an  inspection  of  the  map  and 
records  which  follow. 

Contour  Map  on  the  Austin  Formation 

On  the  accompanying  map  there  is  assembled  the  information 
now  available  on  the  underground  position  of  the  Austin  for- 
mation in  the  San  Antonio  oil  fields.  The  belt  of  surface 
outcropping  of  the  Austin  is  indicated  on  this  map  by  the 
shaded  area.  To  the  east  of  its  outcropping  area  the  position 
of  the  Austin  is  indicated  so  far  as  practicable  from  records 
now  at  hand,  by  contouring,  the  contours  being  in  depth  below 
sea  level  as  indicated.  Likewise  the  location  of  the  wells  used 
in  contouring  is  indicated  and  the  depth  with  respect  to  sea 
level,  at  which  the  Austin  was  found  in  that  particular  well,, 
is  entered  on  the  map. 

In  this  connection  it  should  be  stated1  that  the  surface  eleva- 
tion of  the  various  wells  has  been  taken  largely  from  the  topo- 
graphic map,  although  for  a  number  of  the  wells  not  on  the  topo- 
graphic maps  the  elevation  has  been  determined  approximately 
by  barometer  reading's.  There  is  necessarily  a  small  possible 
error  in  elevation  of  wells,  and  this  should  be  taken  into  con- 
sideration in  using  the  map.  The  possible  error  from  this 
source,  however,  is  probably  less  than  the  average  error  inci- 
dent to  recording  and  interpreting  well  logs,  and  is  probably 
negligible  or  nearly  so  in  regional  mapping. 

In  1920  a  bulletin  on  the  geology  of  Bexar  County  was  issued 
by  the  Bureau  of  Economic  Geology,  in  which  structural  con* 
ditions  were  indicated  by  contouring  on  the  Del  Rio,  a  Lower 
Cretaceous  formation.1  A  comparison  of  the  map  issued  at 
that  time,  with  the  present  map,  shows  that  the  major  struc- 
tural features  recognized  from  the  Del  .Rio  formation,  are  like- 

*The  Geology  and  Mineral  Resources  of  Bexar  County,  by  E.  H, 
Sellards,  University  of  Texas,  Bureau  of  Economic  Geology  and  Tech- 
nology, Bulletin  1932,  March,  1920. 


34  University  of  Texas  Bulletin 

wise  shown  by  contouring  on  the  Austin  formation.  However, 
by  the  aid  of  wells  drilled  during  the  past  two  years,  the  map- 
ping has  now  been  extended  into  Atascosa  and  Medina  coun- 
ties. Accordingly  the  map  now  issued  includes  the  greater 
part,  but  not  all,  of  Bexar  County,  and  a  small  part  of 
Atascosa  and  Medina  counties.  In  the  southeastern  part  of 
Bexar  County  but  little  drilling  has  been  done,  and  in  this  part 
of  the  county  no  progress  in  contouring  the  underground  struc- 
ture has  been  made.  For  this  reason  this  part  of  the  county 
is  not  included  in  the  present  map. 

In  the  map  previously  issued  based  on  the  Del  Rio  forma- 
tion, faulting,  so  far  as  recognized  from  underground  records, 
was  indicated.  The  present  map  has  been  simplified  to  the 
extent  of  not  attempting  to  indicate  such  apparent  lines  of 
faulting.  It  may  be  stated,  however,  that  such  new  records 
as  have  been  added  since  the  first  map  was  published  in  so 
far  as  they  relate  to  faulting  support  the  interpretation  pre- 
viously given. 

Structural  Conditions  as  Indicated  by  Contouring  on  the 
Austin  Formation 

The  outcropping  belt  of  the  Austin  in  Bexar  and  eastern 
Medina  counties  shows  notable  irregularities  of  outline  not 
accounted  for  by  erosion.  Thus  in  the  western  part  of  Bexar 
County  north  of  the  Portranca  public  road  there  is  a  broad  belt 
of  the  Austin  which  extends  in  a  southwesterly  direction  into 
Medina  County.  This  belt  of  Austin  forms  a  ridge  of  much 
greater  elevation  than  the  plains  at  either  side.  The  level  and 
much  lower  land  at  the  north  and  at  the  south  is,  for  the 
most  part,  covered  by  terrace  gravels,  but  such  exposures  as 
are  seen  indicate  the  Taylor  formation.  When  followed  to 
the  southwest,  the  Austin  formation  is  found  to  pass  under 
later  formations.  Again  immediately  north  of  San  Antonio 
there  is  found  a  similar,  although  much  narrower  belt  of  the 
Austin  formation,  extending  into  the  northwestern  part  of  the 
city,  and  forming  the  surface  exposures  seen  in  Brackenridge 
and  San  Pedro  parks.  Surface  exposures  of  the  Austin,  in 


Underground  Position  of  Austin  Formation  in  Oil  Fields     35 


UNDERGROUND 
OF  A  i/JTV/v  FORMATION 
AND  PARTS  OF  MED i HA 
ATASC 03 A  COUNTIES 


Fig.  1. — Map  showing  approximately  the  underground  position  of  the  Austin 
formation  in  Bexar  and  in  the  adjacent  parts  of  Medina  and  Atascosa  Counties. 
Shading  indicates  area  where  the  Austin  is  at  or  near  the  surface,  Contours 
on  the  Austin  chalk.  Contour  interval  500  feet.  Sea  level  datum. 


36  University  of  Texas  Bulletin 

this  locality,  are  found  at  an  elevation  of  800  feet  or  more  above 
sea,  while  both  to  the  north  and  to  the  south  the  top  of  the 
Austin  is  encountered  at  a  much  lower  level.  It  is  thus  ap- 
parent that  these  two  belts  of  Austin  exposures  are  due  to 
structural  conditions.  In  the  case  of  the  Austin  exposures  in 
San  Antonio,  faults  are  observed  which  limit  the  exposures 
at  the  south,  these  faults  giving  rise  to  the  San  Pedro,  San 
Antonio  and  Salado  Springs.  At  the  north  side,  the  Austin 
is  limited  by  faults  with  downthrow  to  the  north  or  by  abrupt 
northwest  dips  in  the  strata.  In  the  case  of  the  broad1  belt  in 
the  western  part  of  the  county,  the  structural  conditions  are 
produced  either  by  step-faulting  or  by  folding.  In  each  in- 
stance the  structural  feature  is  a  southwest  plunging  anticline 
or  fault  block. 

While  these  structural  features  are  observable  at  the  surface 
in  the  central  part  of  the  county,  they  are  more  or  less  ob- 
scured south  of  the  Austin  belt  by  the  non-resistant  character 
of  the  formations  together  with  the  mantling  surface  materials. 
From  examination  of  the  well  records,  however,  it  becomes 
apparent  that  this  type  of  structure,  southwest  plunging  anti- 
clines or  fault  blocks,  is  characteristic  of  the  area  as  far  south 
at  least  as  the  south  line  of  Bexar  County.  Thus  the  fault 
block  seen  from  surface  exposures  in  the  city  of  San  Antonio 
may  be  followed  by  well  records  to  the  oil  and  gas  wells  west 
of  Leon  Creek,  and  possibly  also  as  far  as  the  Medina  River. 
The  Gas  Ridge  field,  which  has  produced  chiefly  gas,  and  in  addi- 
tion a  small  amount  of  oil,  is  obviously  accounted  for  by  this 
structural  feature. 

Another  very  pronounced  structurally  high  area  is  that  found 
at  the  Alta  Vista  oil  field.  At  this  locality  the  Austin  forma- 
tion lies  about  300  feet  below  sea  or  within  about  900  or  965  feet 
of  the  present  surface  (900  log;  965  samples).  Immediately 
north  of  the  Alta  Vista  field  the  Austin  lies  at  a  much  lower 
level,  the  difference  being  so  great  as  to  suggest  the  probability 
of  faulting  with  downthrow  to  the  north.  The  wells  of  the 
Alta  Vista  and  Mission  oil  fields  are  located  within  this  struc- 
turally high  area. 


Underground  Position  of  Austin  Formation  in  Oil  Fields     37 
Relation  of  Producing  Wells  to  Structure. 

The  principal  groups  of  producing  wells  in  this  region  are 
indicated  on  the  map.  These  include  the  Somerset  field,  South 
Medina  and  Yturri  wells,  Alta  Vista  and  Mission  pools,  and 
the  Gas  Ridge  wells.  It  will  be  seen  that  these  producing  wells 
are  associated  with  the  structural  features  of  this  area.  It 
is  probable  that  production  is  controlled  in  some  fields  by  fault- 
ing and  in  others  by  folding.  In  either  case  production  is 
likely  to  come  chiefly  from  the  southeast  slope  of  the  structurally 
high  feature.  That  is,  the  favorable  location  for  a  well  is 
either  on  or  somewhat  east  of  the  axis  of  the  "structure."  This 
is  probably  due  to  the  fact  that  the  structural  features  of  this 
area  are  unsymmetrical,  the  northwest  slope  being  short  and1 
hence  affording  but  little  collecting  area  for  oil.  The  south- 
east slope,  on  the  other  hand,  in  which  the  strata  are  returning 
to  their  normal  southeast  dip,  is  likely  to  be  long  and  thus  to 
afford  a  considerable  collecting  ground  for  oil.  With  regard 
to  the  kind  of  faults  that  favor  accumulation,  it  is  to  be  re- 
membered that  there 'are  many  faults  of  varying  intensity  mak- 
ing up  what  is  known  as  the  Balcones  fault  zone.  Most  of 
these  faults  have  the  downthrow  to  the  southeast,  that  is  in 
the  direction  of  the  regional  dip.  Such  faults,  with  downthrow 
to  the  southeast,  do  not  provide  favorable  conditions  for  the 
accumulation  of  oil,  for  the  reason  that  they  merely  intensify 
the  rate  of  dip  or  descent  of  the  formations  to  the  southeast. 
Some  of  the  faults  of  this  zone,  however,  have  the  downthrow 
to  the  northwest.  In  all  of  these  faults,  the  fault  plane  dips 
towards  the  downthrow  side.  In  the  case  of  a  fault  with  the 
downthrow  to  the  northwest,  it  follows  therefore,  that  the 
"d'rag"  which  is  incidental  to  faulting  amounts  to  or  brings 
about  a  short  abrupt  dip  of  the  formations  in  the  direction 
of  the  downthrow,  or  in  this  instance  to  the  northwest.  These 
conditions,  without  doubt,  explain  the  fact  that  it  is  the  faults 
with  downthrow  to  the  northwest  that  bring  about  conditions 
favorable  for  production,  the  drag  to  the  fault  plane  serving  as 
reverse  dip,  aided  possibly  by  deposition  in  the  fault  plane. 


38 


I'ni  versify  of  Te.ras  Build  in 


Producing  Formations  N 

With  regard  to  producing  formations,  more  or  less  produc- 
tion, or  oil  showings,  have  been  obtained  from  all  of  the  Upper 
Cretaceous  formations  in  this  area  and  possibly  to  some  extent 
from  the  Midway,  which  overlies  the  Cretaceous.  In  the  Somer- 
set field  the  principal  production  is  from  about  500  feet  above 
the  top  of  the  Austin  chalk  and  probably  near  the  contact  of 
the  Taylor  and  Navarro  formations.  The  Lower  Cretaceous  now 
known  to  produce  oil  in  Limestone  and  Caldwell  counties,  is 
present,  underlying  the  Upper  Cretaceous. 

Well  Records 

The  wells  used  in  recording  the  underground  position  of  the 
Austin  formation  are  listed  in  the  following  table.  The  "map 
entry,"  given  in  the  table,  appears  also  on  the  map  and  is  in- 
tended to  assist  in  locating  the  well.  It  records  also  the  eleva- 
tion of  the  top  surface  of  the  Austin  with  respect  to  sea  level 
as  nearly  as  has  been  determined  for  that  particular  locality. 
Thus  the  entry  412  records  the  top  of  the  Austin  as  412  feet 
above  sea  level.  Entries  preceded  by  the  minus  sign,  as  — 1700, 
record  depth  of  the  Austin  below  sea  level.  In  addition  to 
the  logs  used  in  mapping  a  few  have  been  added  in  Bexar, 
Medina,  and  Atascosa  counties,  which  are  beyond  the  area  cov- 
ered by  the  map. 

BEXAR    COUNTY 


Name  of  Well. 

Location. 

Eleva- 
tion. 

Total 
Depth. 

Top  of 
Austin. 

Map 

entry. 

\llen  ,    D     J 

Kelly    Field9 

(80 

1  054 

600 

80 

Applewhite  --   
Arrowhead  Oil  Co... 

1(5  mi.   S  

2%     mi.     W.,     1     mi.     X. 
Somerset 

500 
650+ 

1  ,052 
1,700 

1,896 
i,!TO 

—1,396 
—  920 

Basse,    E.    E  

5  mi.  N.   San  Antonio 

7<K)T 

590 

25+ 

735 

Benke,  Mrs    K 

92  mi    N     W 

1  030T 

1  000 

?00 

730 

Blue   Win?    Club  
Brendle,  H 

12  mi.   S  

527  Bandera  St  ,  S     A. 

490T 
720 

2,444 

1,746 
180 

—1  ,256 
540 

Breckenridge  Well 

Near   Salado    Creek 

630 

1,018 

70+ 

.360 

Brown,  Marathon  Oil 
Co 

2  mi     due  E     Somerset 

625+ 

1   319 

894 

Cassin        

9  mi.  S.  S.  A 

550 

1,468- 

973? 

—  493 

Clamp,    C.    C  

Collins  Gardens 

6  mi.  west  
S.    W    Pt     S     A 

700 
650 

1,452 

C62 
5'75 

38 
125 

Carney,    Glen 

7%  mi.  E.  of  San  Antonio 

650 

1  226 

o30+ 

l-'O 

Elder  and  Wolf  

8%    mi.     S.     S.     A.     (Alt  a 
Vista) 

600 

1.'786 

9'iO+ 

—300- 

Underground  Position  of  Austin  Formation  in  Oil  Fields     39 

BEXAB    COUNTY— Continued 


Nairn'  of  Woll. 

Location. 

Eleva- 
tion. 

Total 
!   Depth. 

Top  of 

Austin. 

Map 

entry. 

Kn'derick   Well       -  -- 

71/.  mi.   S.  W.   San  Antonic 

V           6.» 

1,200 

740 

—So 

901'  Morales  St       S      \ 

250-f 

:425 

(iovonmient         Well, 
\v;>ition  Post 

6  mi     \     E 

7.351 

«,          374 

55H- 

680 

(Government   Well   --- 

Hackberry   St.,   near  Ave 
C  

(•'SO 

729 

258 

431 

Herf     IT 

4  5  mi     W 

C'89 

i  ->e<> 

621 

62 

If;ll    and    Robv 

7.5  mi     S 

625 

1  890 

1  200 

575 

Hofheintz     R     H 

N.   of  Kelly    Field 

680 

1,453 

600 

80 

Iloltz 

9  mi.    S.    W. 

610 

1  665 

1,900-H 

—  575 

Hot  Well* 

4  5  mi     S 

575 

1  878 

990 

115 

Kearney  Oil  and  Pipe 
Line  Co 

12  mi     S     of  S     A 

610 

2  355 

957 

347 

Kreutch     O 

5.5  mi     F     S     A 

678 

1  000 

420+ 

255 

Kurz 

1  mi     S     E     of  Somerset 

638 

1  650 

1  450~ 

SI  2 

Legler,   W.    F. 

5  mi.   W.     

6fl0 

1,555 

670 

95 

Linn  9 

12  mi.   S 

550 

1  443 

1  0°!4 

544 

Lone     Star     Brewing 
Co 

120  Jones  Ave. 

660 

805 

248 

4l9 

La  nun    1,    Ulf-Varnes 
Exploration  Co 

16  mi.    S. 

!           500 

2  693 

9^900-1- 

—  1  700 

Masterson    1,    Meech- 
am    Oil   Co 

18  mi.    W. 

750 

2  245 

255 

495 

.Mclntosh,   Mrs 

7  mi.    E.   of  S.   A. 

700 

668 

30+ 

670 

Mathey  1,   Bexar  Pe- 
troleum  Co 

1  mi.   W.    Losoya 

515 

2  332 

1  892 

1  377 

Medina  Oil  Co 

12  mi.   S. 

530 

1  833 

1  01? 

48° 

M.    K     T     Ry 

Landa 

784 

643 

60+ 

724 

IVrrinot    Well, 
Schlather  Ind. 
Porch  Well 

2  mi.    S.    W.    Martinex  
Iiy2  mi.   S. 

680T 
530T 

1,375 
1,505 

1,239 
Not 

—559 

Ridder     \     J 

13  mi     S     W 

6°8 

2  911 

reached 

900+ 

—975+ 
272 

S.   A.   &  A.  P.  Ry._- 
San  Antonio   City 
Water 

Pro-baa   and   Simpson   Sts. 
Market  St. 

630 

650 

1,103 

880 

500 

2?0 

130 
430 

"San   Antonio   City 
Water 

Conception  Mission  _-  

605 

1,440 

780 

175 

San     'Antonio     Port 

5  mi     N   . 

740 

C67 

60 

680 

Schmidt,   Marathon 
Oil  Co 

1%  mi.   due  E.   Somerset 

635+ 

1  579 

944 

Shatuck   Well 

19th   St.   WT. 

678 

6(i7 

335 

343 

Smith,    Sarach  
Southern  Ice  Co  

2  mi.  E.  S.  E.  of  Somerset 
Frio  and  Durango   Sts  

650± 
655 

1,668 
822 

Not 
reached 
280 

—1,018+ 
395 

Southwest  Land  Cor- 
poration 

4  mi.  W.    

708 

1,000 

390 

318 

Somerset  Well  ... 

Somerset,  cored  by  Kerr  at 

'St     Louis  College 

1600.     Austin  1,560-1,930. 
W.  5.1 

650 

760 

2,320 

7Q9 

1,560 
215 

—910 
545 

"Steves     Mrs     J 

Steves  Garden 

645 

1  185 

604 

41 

'Steves    Mrs    J 

509  King  Williams  St 

645 

758 

250 

395 

Steves     Ed 

8.5  mi.   S.   of  S.  A. 

660 

1  840 

j  300-+- 

(340+ 

'Sullivan,    D. 

3y2  mi.  S.  E-.  of  S.  A  

620 

1,100 

505+ 

115 

Taft,   L    S 

7  mi.   E.   of  S.  A. 

666 

1  240 

880 

215 

Terrell  Hot  WelL- 
Terrell,    J.    H 

5.2  mi.   S.  of  S.  A  
S.  W.  city  limits,  S.  A. 

630 
675 

1,956 
1,140 

1,000 
550 

—370 
12'> 

Texas    Steam    Laun- 
dry. 

205  Losoya  St  

€65 

748 

290 

375 

Tommins,   R.   

South  city  limits,   S.  A.- 

630 

1,500 

900     i 

—270 

Union  Meat  Co  

Laredo    and    Ralph    Sts., 
S.  A. 

640 

1  400 

340 

qnn 

Voght,  Win.  
Walsh,    Meechum   Oil 
Co  

Waring  Well  
Vturri     1,      W.      H. 
Reynolds  et  al  

14,  mi.  S.  W.   of  S.  A.__. 

12  mi.   S.   of  S.  A.—. 
7.5  mi.   N.   W.   of  S.  A._. 

Wz  mi.  S.  San  Antonio— 

605 

550 

920     • 

510± 

1,850 

1,736 
2,853 

3,460 

985± 

1,403 
13 

1,476? 

—380 

—353 
907 

966? 

40 


University  of  Texas  Bulletin 

MEDINA    COUNTY 


Name  of  Well. 

Location. 

Eleva-        Total     ' 
tion.         Depth,    j 

Top  of   i 
Austin,   i 

i 

Map 

entry. 

Blackaller      1,      Mid- 
Ffio  Oil  Co  

5  mi.   E.   and  3  mi.  N.   of 
the     S.     W.     corner     of 
county 

SOOT        3  115 

1  %0 

-1  160? 

W.  Garnand,  Somer- 
set, Western  Oil  Co. 

Thomas   Surv.    516 

745           1  648 

1  550 

805 

Gray  Well 

Abt     1   mi     S     E       I  ytle 

8  mi.,  113%  Tli.  Thomas 

Haas,   Geo.   

414  mi    S    WT     of  Dun!ay 

1  000           1  000 

97  5>    j 

125 

Kimble,  Osman  Oil 
Co  

Near  Devine,  2  mi.   S.  W. 

McClure,   T.   S.,   1— 

S.    Reiden,   John   No.    28 
3  mi.    S.    W.    Dunlay   Sta. 
on  S.  P.  Ry.     See  T.  S. 
McClure,    142  Goliad   St. 

670           2,540 
1,233 

2,287 
740 

—1.617 

ATASCOSA    C01 

JNTY 

Name  of  Well. 

Location. 

Eleva-        Total 
tion.         Depth. 

Top  of 

Austin. 

Map 

entry. 

Caruthers  11,  Gray- 
burg Oil  Co 

About  2  mi.  S.  W.  Somer- 

set 

••>  375 

1  775 

Childress  No.  1,  Lem- 
ing  Oil  &  Gas  Co. 
Now  owned  by  Hol- 
lingsworth,  Pleas- 
an  on 

1  mi.   S.   of  Leming  

450A    .    2,600 

Not 

Foster,  Grayburg  Oil 
Co. 

Somerset  Oil  Field  &&  mi. 

reached 

—2,150+ 

W.  S.  W.  Somerset  Sur- 
vey 523 

745  \ 

1   US; 

Fowler,  Gulf  Produc- 
tion Co.  Powler 
Lease  No.  2  

Somerset   Oil   Field  2.   mi. 

S.  W.  Somerset  

1,8*9 

1,825 

—  1,175, 

Hartung  Loase  1.  W. 
1.  Grayburg  Oil  Co. 

Survey  140,  3  mi.  ±  S.  W. 
Somerset 

1  979 

1  968 

1  °13~ 

Hartune:  17,  Gray- 
burg Oil  Co.  

4%    mi.    S.    W.    Somerset 

Surv.  385,  J.  J.  Knott.. 

2,729 

2,290 

—1,640- 

McCain  Lease  1.    W. 
2.       Grayburg     Oil 
Co  

'  Survey    1,970,     S.     W.     of 

Muennick  Well  2. 
Grayburg  Oil  Co 

Somerset  

Atascosa  County 

1,975 
1  903 

1,973 
1  Q03 

'  —1,323 
1  953 

Richter  1,  Galvan  Oil 
Co  

'l1/^  mi.  N.  E.,  Pleasanton 

E.  H.,,  Timmons  Surv., 
N.    W.    part 

350  \        4  015 

\}Qt 

'    reached 

—3,665+ 

AN  INITIAL  FINE  OF  25  CENTS 


OVERDUE. 


LD  21-100m-7,'3! 


Binder 
Gaylord  Bros-  !««• 

St,ckton,  Calif. 
T.M.  Rea-U.  S.Pat-  Off 


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